Sri Lankan government is fully committed to the process of direct negotiations with the Tamil Tiger rebels despite a rebel suicide attack which killed five people and caused injuries to 12 others, Prime Minister Mahinda Rajapakse said on Wednesday.

"We are committed to the peace process but all parties must extend their cooperation," Rajapakse told a local radio without making a direct reference to the Tamil Tiger rebels.

The suicide attack on Wednesday noon at the Kollupitiya police station in the heart of capital Colombo near the prime minister's residence was the first such attack by the Liberation Tigers of Tamil Eelam (LTTE) rebels since they entered truce with the government in February 2002.

The female LTTE member was roaming around the nearby office of the Hindu Religious Affairs Minister Douglas Devananda, who is a bitter opponent of the LTTE, for his arrival when the police nabbed her.

The female suicide bomber suddenly blew herself up when she was subject to a body search by the policewomen, military spokesman Sumedha Perera said.

He confirmed that four police personnel were killed and seven others including three policewomen were among those injured.

The attack came amidst efforts by the Norwegian peace facilitators to revive the peace process on hold since April last year.

The government has condemned the suicide attack and said that violence must not be used to resolve disputes.