BURDWAN: Two suspected Indian Mujahideen militants were killed and a third injured critically in West Bengal's Burdwan town when an IED they were allegedly making exploded in the house of a Trinamool Congress leader which also doubles as the local party office.

The blast took place on Thursday afternoon.

Locals say that when police arrived, two women held them off at gunpoint threatening to blow up the house and delaying them long enough to burn several documents and evidence. Among the half burnt papers found later were leaflets of al-Qaida leader Ayman al-Zawahiri and Indian Mujahideen. Only a month ago, Zawahiri had warned of 'jihad' in India.

Police sources said 55 IEDs were seized along with RDX, several wrist watch dials, maps and SIM cards. Some half-burnt books were in Arabic, say police sources. Security agencies believe that since the militants were already assembling IEDs, they planned to hit an Indian city in a few days.

NIA, IB and other central agencies are already in Burdwan but say they are getting no cooperation from the state police. Local cops are accused of trying to hush up the blast. They destroyed the seized IEDs, bombs and explosives on Friday before central investigators could arrive. SP SMH Meerza claimed those dead did not have any criminal antecedents and that the bombs were crude socket-bombs. But CID inspector Amar Kumar Mondal, who led the bomb squad, said he defused 55 IEDs and RDX.

While Shakeel Ahmed from Nadia was killed on the spot, East Midnapore's Shobhan Mondal died in hospital. Hasan Saheb of Murshidabad is in critical condition. Shakeel's widow Rumi Biwi and Hasan's wife Amina Biwi have been detained along with landlord and Trinamool leader Nurul Hasan Choudhury. The Opposition BJP and CPM demand a probe into the "Trinamool-terror nexus".

The blast took place around noon on Thursday. Fire brigade and police believed they were responding to a domestic fire and were shocked to see two women brandishing revolvers and threatening to blow up the house if they dared enter.

In an instant, a 'cylinder blast' had transformed into a national security issue. Locals say they saw the two women burn several documents before they let police enter after an hour. Police took away the IEDs in sand-laden trucks. It took seven hours for a CID team from Kolkata to destroy them in controlled detonation the next morning.

When central agencies arrived on Friday afternoon, they were stunned to learn that the IEDs and RDX had been destroyed.

A four-member IB team was the first to arrive from New Delhi. An IB inspector alleged that Burdwan sadar police were not cooperating with them. "Neither the Burdwan SP nor the thana is helping us. They have destroyed all the bombs and explosives instead of retaining them for examination. The case will now become useless because of lack of evidence. The seized explosives would have been crucial in the case," he said.

An NIA team arrived on Saturday, followed by a Central Forensic Science Laboratory team from Hyderabad. CFSL's P D Ganesh said that the sand samples collected from the detonation site on the riverbank point to Indian Mujahideen. He said that police should have kept the explosives, and waited for them instead of destroying them. NIA and CFSL experts entered the house for the first time around 12pm on Saturday, two days after the blast.

The ruling Trinamool Congress is in a tight spot because the house served as its local party office. Trinamool leader Nurul Hasan has told police that he had given the first floor on rent to Shakeel Ahmed for Rs 18,000 three months ago and claims he does not know the others.

BJP district secretary Sandeep Nandy has demanded a CBI probe. "NIA and CBI should interrogate the three detainees and the injured person. The house is the local party office of Trinamool and you can see its flags even today. Burdwan SP SMH Meerza is trying to hush up the incident, claiming police have seized 15 crude bombs. He is trying to save the Trinamool leader. The Trinamool-terrorism link should be probed. This is a very serious matter," Nandy said.

CPM leader Amal Haldar said burnt papers posters of Indian Mujahideen have been found. "The Trinamool-terror link has now been proved. We demand an NIA probe," said Haldar.

Shakeel was in Mumbai for a long time before coming to Burdwan, sources say. IGP-CID R Shiva Kumar and IGP-western zone Siddhinath Gupta are interrogating the three detainees. "We have told the women to call their guardians. All 55 crude socket bombs have been destroyed by CID yesterday. The victims have no criminal background. The condition of the third victim is serious," Meerza said.