An operation by the Indian Army in Dhubri district of north-eastern Assam state on Friday resulted in seven Islamic militants being killed, a Ministry of Defense release said.

The group of terrorists belonged to a Bangladesh-based unit of the Harkat-ul-Jihad-al-Islami (HUJI) group and was planning to carry out several bomb blasts in Assam, the statement said.

The group had moved across the border from Bangladesh and were moving towards Assam's main city Guwahati when they encountered the soldiers.

The gunbattle in Dhubri district, 300 kilometres west of Guwahati, lasted for about 45 minutes. "All seven terrorists were gunned down," the release said.

Seven automatic pistols, three radio sets and a large quantity of explosives, mainly gelatin, and detonators, were recovered from the dead militants. They were also carrying large amounts of Bangladeshi and Chinese currency.

The army statement said the operation was launched after information gathered through mobile interceptors indicated that the group from Bangladesh were on their way to Guwahati to meet another group already stationed there to engineer the blasts.

India has an unfenced border with Bangladesh and the rivers in the border region are poorly patrolled.

Several separatist militant groups operating in north-eastern India have been known to move back and forth from Bangladesh in the past.

According to Indian intelligence reports, Islamic militant groups have also been moving men and explosives across the Bangladesh border over the past few years.

There have been a series of bomb blasts in three major Indian cities this year including national capital Delhi.