A homicide bomber apparently targeting a provincial governor in southwestern Afghanistan on Monday killed six policeman and the governor's son while wounding 14 other people, officials said.

The blast in Nimroz province happened as Afghan troops in the capital, Kabul, thwarted another bomber intending to set off his explosives-filled vest inside a bus carrying army soldiers. Afghan TV showed police cutting the wires on the vest as the would-be bomber was still wearing it.

Insurgents have launched more than 130 homicide attacks in 2007, a record. Most of the attacks target government officials and international forces, but most of the victims are civilians.

The bomber in southwestern Nimroz province detonated the explosives strapped to his body outside the governor's house in the town of Zaranj as people were coming into work, said the provincial deputy governor, Maluang Rasooli.

Gov. Ghulam Dastagir Azad said he was the target of the attack, which killed his son.

Six officers were killed and 14 other people, including nine policemen, were wounded, Azad said. The bomber also died.

Afghan security forces, meanwhile, arrested a potential homicide bomber as he attempted to board an army bus in Kabul, Interior Ministry spokesman Zemeri Bashary told reporters.

Authorities have been wary of attacks targeting army or police buses in Kabul after two such attacks this year.

The attacker was from the Pakistani city of Peshawar, Bashary said. Afghan and Western officials say many homicide bombers are trained in neighboring Pakistan and then cross the border into Afghanistan to carry out their attacks.

An Afghan soldier kicked the man as he tried to board the bus, and when the attacker fell down, he was unable to detonate his suicide vest, said Kabul police chief Mohammad Salim Hasas.

The officials displayed the defused suicide vest for the media and said the attacker was undergoing blood tests because he appeared to be under the influence of drugs. Hasas said the attacker's identity would not be revealed in hopes he would inform on other attackers.

More than 6,000 people have died in insurgency-related violence this year — a record number, according to an Associated Press count based on figures from Western and Afghan officials.

In southern Helmand province, Taliban attacked a police checkpoint on Sunday, killing two officers and wounding four others, said provincial police chief Muhammad Hussein Andiwal.