Colombo, Feb 2: At least 20 people were killed and many others were injured when a powerful explosion occurred in a packed bus, carrying civilians, in central Sri Lanka today.

The blast occurred at a bus station in Dambulla, police said, adding that the bus had stopped on its way from Kandy to Anuradhapura.

According to military spokesperson Brigadier Udaya Nanayakkara, Tamil Tiger rebels were responsible for the attack, reported the BBC.

The attack comes in the midst of increased security ahead of celebrations on Monday to mark the 60th anniversary of Sri Lanka's independence from Britain.

The Tigers have been fighting for an independent State in the north and east of Sri Lanka since 1983. The civil war there has heightened since last month, when the government pulled out of a ceasefire with the rebels. (ANI)