Forensic experts at the blast site. A Telegraph picture

Siliguri, April 16: Police have detained four women for questioning and raided the rented house of one of the eight persons arrested in connection with the Champasari blasts and the subsequent recovery of explosives from Mallaguri and Gurung Bustee.

In another development, a forensic team from Calcutta visited the house in Champasari’s Naya Bustee where two concurrent blasts had killed three alleged bomb-makers on April 3. The experts are here to determine the nature of the explosives.

The four women detained today were picked up from Bidyachakra Colony, located close to Mahakalpally, on the southern bank of the Mahananda. Another woman, Krishna Gajmer’s house in Mahakalpally was raided after her landlord, Ashok Bhattacharya, saw her picture taken after her arrest in different media and contacted the police.

“He told us that Gajmer was a tenant at his house in Ward 10 of the Siliguri Municipal Corporation,” said Tapan Alo Mitra, the officer investigating the blasts and explosives case. “So we raided the room along with the bomb disposal squad of the CID and the dog squad and recovered a photo album, a few documents and a diary. But no explosives were found.”

A search is on for Gajmer’s room-mate, Binu.

The police said the album contained photographs of the woman whose picture Pradhannangar police had released on Monday as a key suspect in the case. A woman was killed in the blasts but since her face was blown off, it is not known if she was the one in the picture.

The sources added that Fulmaya alias Ganga Gurung, a Bhutan Communist Party (Marxists-Leninist-Maoist) member arrested on Monday, used to visit Gajmer’s place frequently. Gajmer and three others arrested yesterday allegedly have links with the extremist organisation, of which Dipen Rai, the sole survivor of the Champasari blasts, is a member.

Dipen is in jail with two of his associates. He was arrested on the day of the blasts.

This morning, officials of the Central Forensic Science Laboratory (CFSL), Calcutta, collected ashes and remnants from the Champasari blast site. “We can confirm the nature of the explosives only after conducting tests in the laboratory,” Anupama Bosu, a senior scientific officer at CFSL, said.