Separatist rebels bombed a gas pipeline and blew up a petrol storage tank in India's oil-rich Assam state in pre-dawn raids today and said they would stage more attacks in coming days.
Police said the strikes were the biggest for two years against oil installations in Assam by rebels fighting for independence for the state of 26 million people.
The threat of more strikes by the United Liberation Front of Asom (ULFA) prompted tighter security at oil installations and other key sites across Assam which produces more than five million tonnes of crude annually - 15 percent of India's total onshore output.
The rebels also bombed a natural-gas pipeline belonging to state-run Oil India Ltd in Duliajan, 20 km (12 miles) from the Indian Oil refinery.
ULFA's commander-in-chief Paresh Barua told reporters the group staged both attacks and planned more. "We've carried out these strikes to register our protest against Indian rule," he said, adding the group had "orders to continue such targeting in the coming days. We're going to target oil installations and security forces."
The plant is one of India's smaller refineries with annual production capacity of 650,000 tonnes or 13,400 barrels per day.
There were no estimates of the cost of the damage.