COLOMBO, Sri Lanka - A suicide bomber triggered an explosion Friday outside an eye hospital in central Colombo, killing himself and six others a few minutes after the health minister and World Health Organization officials had driven by.
No one claimed for responsibility for the blast, which injured 24 people, four critically.
But police blamed the Liberation Tigers of Tamil Eelam rebel group, which has a suicide squad and often carries out such bombings. The rebels, who seldom comment on such attacks, have been battling for a separate area for the minority Tamils in the north and east since 1983. More than 62,400 people have been killed in the war.
Health Minister Nimal Siripala de Silva told The Associated Press he thought he was the target of the attack.
''I passed that way just seven minutes before the blast. I suspect I was the target,'' de Silva said.
Shortly before the explosion, World Health Organization officials also drove past the area for a scheduled meeting with de Silva at the Health Ministry. The ministry's offices are located next to the Eye Hospital.
Fire Department Chief R. K. Nissanka said the bomber triggered the explosion when a policeman approached him for questioning. A civilian had told police the man was acting suspiciously.
''I heard a big noise and covered my face with my hands and fell down. All I saw was people running everywhere,'' said J.W. Ariyawansa, who was heading into the Eye Hospital for treatment at the time of the blast. His right hand was badly injured and a piece of shrapnel lodged in his head.
The suicide bomber and the policeman were killed instantly in Friday's attack. Three people died en route to the National Hospital, and two died after arriving in the emergency ward, said Pushpa Soysa, head of the nurses training unit. Of the 24 injured, 10 underwent surgery and four were in critical condition, Soysa said.
Within hours of the blast, a special police team were searching hotels in the city for suspected LTTE members, said Bodhi Liyanage, deputy inspector general of police.
''It is an emergency operation and will continue until late in the night,'' he said. State television reported that four persons were arrested.
The rebels have been blamed for three bombings in the capital this year. In January, a suicide bomber blew herself up near the prime minister's residence. In March, 31 people were killed in a bombing and shootout near Parliament. In June, a Cabinet minister was assassinated by a suicide bomber.
President Chandrika Kumaratunga was blinded in her right eye last Dec. 18 when a suicide bomber tried to assassinate her at an election rally, when 25 people were killed and more than 90 were injured.
The rebels have also been blamed for the suicide bomb assassinations of former Indian Prime Minister Rajiv Gandhi on May 21, 1991 and Sri Lankan President Ranasinghe Premadasa on May 1, 1993.