GUWAHATI: Suspected separatists in northeast India set off two explosions on Sunday killing five people and wounding 50 more, police said, as two of the movement's leaders remained under arrest.

The blasts hit Nalbari town, about 70 kilometres (45 miles) west of Guwahati, the main city in restive Assam state.

A police spokesman said the outlawed United Liberation Front of Asom (ULFA), which has been fighting for an independent homeland since 1979, was likely to be behind the explosions.

Two senior ULFA leaders were arrested last month while allegedly trying to enter Assam across its border with Bangladesh.

"The sound of the first blast was deafening," said witness Biplab Barman. "The second explosion took place in front of our eyes with many people who came rushing to the site of the first explosion getting injured."

On Monday, suspected separatists blew up a fuel-laden train in the state, causing a giant inferno that took 12 hours to control.

The insurgency in Assam and surrounding states has claimed about 10,000 lives over the past two decades.

More than two dozen rebel groups in the oil-rich region are fighting for secession.