A Sri Lankan suicide bomber killed 22 people including a retired army general who is the provincial leader of the main opposition party, police said on Monday.

The bomber walked into the opening of a new office for the opposition United National Party (UNP) in the north central town of Anuradhapura, 200 km (124 miles) north of the capital Colombo, attended by retired Major-General Janaka Perera, police said.

'A suicide bomber went inside and exploded. My senior officer there said 22 people were killed and among the dead were Janaka Perera and his wife,' Deputy Inspector General KPP Pathirana told Reuters.

Perera in August unsuccessfully ran to be chief minister of the province, a powerful local position.

Police had no immediate suspects in the attack. But the rebel Tamil Tigers have assassinated many politicians over the years using suicide bombers, a technique they have perfected during their 25-year war to establish a separate homeland for Sri Lankan Tamils.

The military is on the edge of their headquarters town of Kilinochchi, a strategic and symbolic prize in an intensifying war in which the military is growing increasingly confident of a conventional victory. - Reuters