Further investigations led to the arrest of three of Nasir's accomplices in Siliguri, West Bengal, on Sunday. Six others -- four Egyptians, one Burmese and one Sudanese -- are, however, absconding. Delhi Police Commissioner V.N. Singh today said that the six are members of Saudi millionaire and terrorist leader Osama bin Laden's group. They reportedly entered India along with Nasir in October last year and are currently suspected to be based in Chennai.

Sources added that US investigators have joined hands with the Delhi Police in questioning Nasir. The US team is especially interested in Nasir's absconding associates as one of the Egyptians, Mustafa, allegedly masterminded the bombing of a US consulate in Thailand last year.

Nasir has reportedly told the police that he was initiated into terrorism in 1991 through the International Islamic Relief Organisation in Bangladesh. The police commissioner said this organisation is based in Pakistan and funds terrorist training camps in Pakistan Occupied Kashmir and Afghanistan.Singh added that Nasir was recruited by the ISI in 1996 and trained and sent to Siliguri to build contacts. He was later asked to shift to Calcutta and collect intelligence about army installations of the Eastern Command.

In September 1998, Nasir reportedly met Abdul Karim Tunda, who allegedly masterminded the series of bomb blasts in Delhi and is now believed to be dead, members of the ISI-funded terrorist group Lashker-e-Toiba and several other people in Bangladesh.

The gathering reportedly hatched a plan to blow up US consulates in Chennai and Calcutta. For Delhi, the group planned a series of explosions on the eve of the Republic Day celebrations.

Singh said Nasir and his six associates from Osama bin Laden's group stayed in Calcutta for almost a month until the first week of November after crossing the Bangladesh border. While Nasir came to Delhi thereafter, the others shifted to Chennai.

The police commissioner said the Crime Branch has traced the source of the RDX, which was supplied to Nasir to begin a series of explosions. Nasir has been booked for waging a war against the country as well as violating the Explosive Substances Act.