A soldier secures the site of a suicide bomb explosion in the north-central Sri Lankan town of Anuradhapura on Monday. The bomber killed 22 people including a retired army general who is the provincial leader of the main opposition party, police said. (Reuters)

A suspected Tamil separatist suicide bomber triggered a blast that claimed at least 27 lives in northern Sri Lanka on Monday, among them a celebrated former army general and his wife.

At least 80 more were wounded in the explosion at the regional office of the opposition United National Party in the town of Anuradhapura, said army spokesman Brig. Udaya Nanayakkara.

The attack occurred around 8:45 a.m., said Nanayakkara, as United National Party officials gathered to open a new office. The bomber went into the office and blew himself up, killing retired general Janaka Perera and his wife, Deputy Inspector General K.P.P. Pathirana told Reuters.

The bomber was likely a member of the militant separatist group Liberation Tigers of Tamil Eelam, said Nanayakkara. The Tamil Tigers have been waging an armed fight to establish an autonomous Tamil-governed region in the island, separate from the Sinhalese majority.

There have been no reports so far of the group claiming responsibility for the attack.

Perera a controversial figure

The bomber was likely targeting the controversial Perera specifically, partly because of his past efforts to quell separatist forces, said Nanayakkara.

Perera is most notably known for halting a rebel offensive in 2000 in the Tamil heartland of Jaffna, a success that earned him fame and plaudits throughout the country.

After winning a seat in the North Central provincial election in August, last month Perera ran unsuccessfully for the position of chief minister of Northern Central province in a move widely seen as an attempt to kick-start a charge toward the party's leadership post.

UNP officials spoke out Monday against the ruling government for not doing enough to ensure the security of Perera and other party members who were believed to be among the dead and injured.

The bombing came just hours after another bomb exploded by a roadside in a village near Arunadhapura, killing two,

"The government must take full responsibility. They did not give him adequate security for political reasons," party official Tissa Attanayake said, without elaborating.

Perera had often criticized President Mahindra Rajapakasa's government for the way it conducted military operations against the rebels.

The blast on Monday came as government troops and Tamil Tiger fighters battled for control of the rebels' administrative capital in the northern town of Kilinochchi.

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

Fighting on Sunday killed 17 rebels and wounded 30, while one soldier was killed and eight were wounded, the military said. And on Monday, air force jets bombed a strategic Tiger artillery position on the northwestern coast, the air force said.

The prospect of victory has raised fears the rebels will increase their bombing campaign in Colombo and elsewhere in response to losing the turf they have held and ruled for years as a de facto state in the island's north.

In a quarter century since the Tamil Tigers began their armed efforts to win autonomy, an estimated 70,000 have lost their lives as a result of the group's conflict with the government.

With files from Reuters and the Associated Press