Colombo  - Ten people, including eight police, were killed and 90 others injured in a bomb explosion when a suicide bomber drove a motorbike into a bus carrying police personnel in central Colombo, the Ministry of Defence reported.

The explosion went off near a security checkpoint on the road leading to the president's office within a high-security zone at noon (0630 GMT), army spokesman Brigadier Udaya Nanayakkara said.

It happened 150 metres away from the president's office. Two of those killed and many of the injured were civilians, said the defence ministry.

Dr Hector Weerasinghe, director general of National Hospital, said that more than 90 bomb victims have been admitted to the hospital, and 36 of the injured were police personnel.

The incident took place behind the Colombo Hilton Hotel, but there were no reports of any injuries to tourists.

Initial reports said that a three-wheeler packed with explosives had rammed a police bus which was parked on the road, but a police officer injured in the incident said he observed a motorcycle coming and ramming the bus.

The Ministry of Defence claimed the Liberation Tigers of Tamil Eelam (LTTE) rebels were responsible for the attack.

The police were assembling to provide security for a planned opposition demonstration ahead of the swearing-in of the newly-elected chief minister for the eastern province.

Sivanesathurai Chandrakanthan, a member of the Tamil Makkal Viduthalai Puligal (TMVP) party, a breakaway group of the Tamil Tigers, has been picked as the chief minister for the eastern province.

The opposition United National Party (UNP) went ahead with the demonstration elsewhere in the capital, claiming that the ruling United People's Freedom Alliance (UPFA) had rigged the poll.

The military ousted Tamil rebels in military operations earlier this year and provincial elections were held there Saturday.

Similar military operations are in progress in the northern province to recapture rebel-held areas.

Security in the capital has been strengthened with additional checkpoints since the explosion. (dpa)