Rebels in India's northeastern state of Assam blasted an oil pipeline yesterday while a militant was killed amid increasing violence before the country's Independence Day celebrations, police said.

The pipeline of state-owned Oil India Limited was blown up early Sunday by suspected militants of the outlawed United Liberation Front of Asom (Ulfa) in Assam's Sivasagar district, a police official said.

The 1,150 kilometre (713 mile) pipeline supplies crude to a refinery at Barauni in the eastern state of Bihar.

The police official, who did not wish to be named, told AFP by telephone that around 15 militants arrived at an area where the underground pipeline is exposed around 30 minutes past midnight on Sunday and overpowered four security guards.

"The militants tied the guards to a lamppost and planted explosives beneath the pipeline before detonating them," he said.