MOGADISHU, Nov 30: Three suicide car bombers, among them a veiled woman, killed themselves and three companions at a police checkpoint outside Somalia's government base of Baidoa, a senior official and a police officer said on Thursday.

''Three cars have arrived at government checkpoint and as the police tried to check them, they exploded,'' Deputy Defence Minister Salad Ali Jelle said.

''The three drivers were killed on the spot and three others who were with them,'' the minister said by telephone. ''We have captured three who were with them who have tried to flee. The dead include non-Somalis, they are Al Qaida supporters.''

A woman suicide bomber wearing a veil detonated herself in one of the vehicles, said a police officer on condition of anonymity because he was not authorised to speak to the media.

He said four civilians were taken to a Baidoa hospital.

Another policeman at the scene, Mohammed Ahmed Mohamud, told said the three captured men appeared African but not Somali. There have been numerous reports of foreign Islamic radicals coming to Somalia to join jihad.

No one claimed responsibility.

On Sept 18, a suicide car bomber tried to kill President Abdullahi Yusuf. The president escaped unharmed; 11 people were killed in the explosion and a subsequent gunbattle, including Yusuf's younger brother.

The transitional government blamed the Sept 18 car bombing on extremists within the Islamic movement. The group denied it was behind the bombing and no one has claimed responsibility.

Tensions are high in this Horn of Africa nation where the Islamic movement and the Ethiopian-backed transitional government are vying for control. Analysts fear a war could engulf the region.

The Islamic movement's spokesman Sheik Abdirahim Ali Mudey said that he was consulting with other senior officials before the group would comment.—AP