From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the continent. Behind that line lie all the capitals of the ancient states of central and eastern Europe. Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest and Sofia, all these famous cities and the populations around them lie in what I must call the Soviet sphere, and all are subject in one form or another, not only to Soviet influence but to a very high and, in many cases, increasing measure of control from Moscow.

Talk to people manning the anti-government barricades and taking part in the demonstrations against Kiev here, however, and one thing in particular is scary. After a day or two you realize that they all say more or less the same thing. “We want to be listened to,” people say. The government in Kiev, which took power after the pro-European revolution there, is a “fascist junta” backed by Europe and the US.

It is as though the Russian media—which is widely watched and read here—has somehow embedded these messages into the heads of people and they have lost the ability to think for themselves. Those who are angry talk as though they were a long persecuted minority, as if they have forgotten that easterners under former president Viktor Yanukovych ran the country until February. Everyone here has been robbed blind by politicians in a system that was as corrupt as can be, but all that seems to be registering right now is a nationalist and hysterical drumbeat from Russia about the new Nazis of Kiev and their Nato masters.

Now the Russian media says the fascists have returned. And of course, just as there were indeed then some admirers of Croatia’s wartime fascists, there are some right-wing nationalists in Ukraine now; the big lie is to give them a significance they simply don’t have.

"We regret any disruptions that the institutions, their cardholders or merchants may experience," Visa said in a statement. "All of Visa's systems are processing normally, and we continue to service our other unaffected Russian clients."

Rival MasterCard Inc said yesterday it would suspend services in the near future to cards issued by SMP bank and InvestCapitalbank.

InvestCapitalbank and SMP bank are controlled by the Rotenberg brothers, Boris and Arkady.

The Rotenbergs, linked to big contracts on gas pipelines and at the Sochi Olympics, were named on a previous US sanctions list issued in March after Russia annexed the Crimea region of Ukraine.

Russia recently revived plans to develop its own card payment system to cut its dependence on Visa and Mastercard .

Home secretary Theresa May, co-hosting the Ukraine Forum on Asset Recovery at Lancaster House with US attorney general Eric Holder, said that the meeting was a "tangible manifestation" of determination not to allow impunity to leaders who loot the assets of their own countries.

Asked whether the White House was considering targeting the personal assets of Russian president Vladimir Putin himself, Holder said: "We believe that Russia must cease its illegal intervention and its provocative actions in Ukraine and we remain prepared to impose further sanctions if that doesn't occur."

Ukraine's general prosecutor Oleh Makhnitskyi told the London forum that the country has already identified stolen assets totalling at least 35bn Ukrainian hryvnias (£1.8bn) and expects the eventual total to amount to tens of billions of US dollars. Funds are believed to have been transferred to international bank accounts in countries around the world.

Describing the Yanukovych regime as an "organised criminal group" whose tentacles reached throughout the administration, Makhnitskyi said: "The new government was set up and we found that our treasury was empty and the funds were misappropriated."

Holder announced the creation of a kleptocracy squad within the FBI tasked with "aggressively investigating and prosecuting corruption cases not only in Ukraine, but around the world".

May said officials from Britain's National Crime Agency and Crown Prosecution Service have already travelled to Ukraine to offer their assistance.

The EU sanctions on 15 Russian officials announced Tuesday lacked the punch of the preceding US sanctions, since they did not target officials overseeing Russia's state-owned oil giant Rosneft or the assets of Kremlin-connected oligarchs.

However, they did target General Valery Gerasimov, chief of the Russian general staff, deputy prime ministerDmitry Kozak, who has been charged with developing Crimea, and several leaders of the pro-Russian militia and protestors who have been occupying buildings in eastern Ukraine. EU countries depend heavily on Russian oil and gas exports.

Among the pro-Russian leaders, most of whom were little-known before the wave of unrest, was Igor Strelkov, cited by some media as the head of the Donbass People's Militia. He is also reputed to be one of the “little green men” Russia has allegedly sent to promote unrest in eastern Ukraine, and EU officials identified him as a Russian military intelligence officer and an advisor to Crimean PM Sergei Aksyonov.

Denis Pushilin, the prime minister of the self-declared “Donetsk People's Republic,” was also included on the list. Little-known before the occupation of the Donetsk regional administration building, Pushilin previously worked for MMM, a company that ran a notorious pyramid scheme in the 1990s.

After Russia, Ukraine, the United States and the EU negotiated a plan in Geneva to defuse the crisis in Ukraine, Pushilin refused to recognise the agreement, saying the Donetsk protestors would refuse to leave the buildings they've taken until the Kiev government leaves its buildings, and they hold a referendum on the region's fate.

Several other pro-Russian leaders from Donetsk also fell under sanctions. Little is known about Andrei Purgin, besides the fact that he is a pan-Slavic activist who has agitated against the new pro-western government in Kiev. According to a social network page apparently belonging to him, he holds an IT degree from a Donetsk university and is now the co-chairman of the Donetsk People's Republic.

Sergei Tsyplakov is reportedly the deputy head of the Donbass People's Militia and is also apparently a long-time pro-Russian activist. He told Russian state news agency RIA Novosti that he was “extremely proud” of his inclusion on the list, adding that the sanctions are laughable.

Two protest leaders from the neighbouring Luhansk region, where heavily armed men have been holding the regional security service headquarters, also face visa bans. Valery Bolotov, a commander of the Army of the Southeast group that has been occupying the building, was announced as the “people's governor” of Luhansk last week. The protestors soon followed Donetsk's example and declared a “Luhansk People's Republic.”

German Prokopyev is also reportedly a leader of the Luhansk militia, but even less is known about him than about the other pro-Russian leaders.

I am alarmed by the worsening security situation in Eastern Ukraine. The downward spiral of violence and intimidation undermines the normal functioning of the legitimates tate institutions. A number of people have been killed, wounded, tortured or kidnapped in the last few days. I notably condemn the shooting of mayor of Kharkiv Henadiy Kernes yesterday and the detention of military observers from OSCE participating States in Slavyansk by armed separatists since last Friday. All persons still illegally detained by armed groups in Eastern Ukraine need to be immediately released. I am also concerned about continued attacks on journalists and the deterioration of media freedom environment in Eastern Ukraine, including the illegal seizure of TV transmission towers.

Vyacheslav Ponomaryov told Interfax news agency the imposition of visa bans and asset freezes against Denis Pushilin, leader of the self-styled People's Republic of Donetsk, and Andrei Purgin, another leader in the eastern region, "was not conducive to dialogue".

"We will resume dialogue on the status of the prisoners of war only when the European Union rejects these sanctions," he said. "If they fail to remove the sanctions, then we will block access for EU representatives, and they won't be able to get to us. I will remind my guests from the OSCE about this."

The six observers were in Ukraine under the auspices of the Organisation for Security and Cooperation in Europe (OSCE), a democracy watchdog. They were detained last week after separatists said they had found a Ukrainian spy with them.

Russia has called back military forces who were conducting exercises along the Ukraine border, news agency Interfax reported. Defence minister Sergei Shoigu told this to his US counterpart Chuck Hagel in a phone conversation, it said.

"As soon as the Ukrainian authorities announced they didn't have any intention of using regular military units against the unarmed population, Russian divisions were returned to their home bases," the Defence Ministry said in a statement on Monday.

Shoigu said Russia had announced the exercises on 24 April after the Kiev government concentrated 80 tanks, more than 130 fighting vehicles and transports and more than 60 artillery pieces in southeastern Ukraine.

Yury Sydorenko, director of information at Kharkiv city council, said in a statement that Israeli doctors decided after examining his wounds that mayor Gennady Kernes, who is Jewish, could be transported.

"At half past two, he was driven to the airport," Sydorenko added.

The shooting of Kernes in Ukraine's second-largest city was the latest violent incident in the east of the country where authorities have launched what they call an "anti-terrorism" operation against pro-Russian separatists.

He appeared to be targeted by a sniper although the exact circumstances and motivations behind his shooting remained unclear.

Locals officials say he was cycling but his entourage said he was jogging. The city council said he was "hit by a bullet in the back".

The doctor who performed emergency surgery on him, Valeriy Boyko, said the mayor's life was "in danger".