June 16 (Bloomberg) -- A suicide bomber attacked a police station in northern Sri Lanka today, killing 12 officers and injuring 23 people including a school girl, the military said.

The bomber, riding a motorcycle, detonated explosives outside the building at about 7:10 a.m. in the town of Vavuniya, the Defense Ministry said. It blamed the rebel Liberation Tigers of Tamil Eelam for the attack that included three female police officers among the dead.

``The LTTE targeted both the police and civilians by carrying out this attack on the main road,'' military spokesman Udaya Nanayakkara said by telephone from the capital, Colombo. The blast came ``when a change of duty took place.''

The LTTE has been fighting for 25 years for a separate Tamil homeland in the island's east and north in a conflict that has killed more than 70,000 people. The Tamil Tigers hold bases only in the north after losing control of the Eastern Province almost a year ago.

Clashes in the north since June 13 between government forces and LTTE fighters killed 28 rebels and eight soldiers. Sri Lanka's military is staging almost daily attacks on the LTTE's estimated 7,000 fighters in the region.

Soldiers began attacking the suspected hideout of Tamil Tiger leader Velupillai Prabhakaran on June 12, the military said at the time. The offensive took place near Mullaittivu in the northeast.

Eradicating Terrorism

President Mahinda Rajapaksa's government has vowed to eradicate terrorism on the island while seeking a settlement with all Tamil groups. It ended a 2002 cease-fire with the LTTE in January, prompting the United Nations to call on the government and the Tamil Tigers to prevent an escalation of violence against civilians.

The blast at the police station comes 10 days after the government blamed the rebels for bombing a bus outside Colombo, killing 22 civilians and injuring more than 50.

Tamils make up 11.9 percent of Sri Lanka's 20 million people and Sinhalese almost 74 percent, according to a 2001 census. The LTTE is listed as a terrorist organization by the U.S., India and the European Union.

To contact the reporter on this story: Michael Heath in Sydney at mheath1@bloomberg.net.

Last Updated: June 16, 2008 00:10 EDT