A man with explosives hidden beneath his clothes blew himself up near a powerful warlord in northern Afghanistan (search) on Thursday, wounding more than 20 people but not the apparent target, officials said.

In another incident underlining the country's shaky security, suspected Taliban (search) militants killed the driver of a truck delivering fuel to a U.S. military base.

The suicide bomber tried to approach ethnic Uzbek strongman Abdul Rashid Dostum after open-air prayers on the Muslim festival of Eid al-Adha (search) in the northern city of Sheberghan, a member of Dostum's security detail told The Associated Press.

"When the bodyguards stopped him from getting any closer, he blew himself up," Jawed, the security guard, said by telephone.

Jawed, who like many Afghans uses only one name, said Dostum was shaken by the noise and the smoke from the explosion but was otherwise unharmed.

Roz Mohammed Noor, the provincial governor, said 23 people were injured by the blast, which occurred as hundreds of people who had gathered in a park were shaking hands and kissing to mark the start of the three-day Muslim feast.

Six people were in serious condition in the city hospital, two of them in a coma, said Noor, who had bent down in the crowd to put on his shoes when the blast occurred, possibly sparing himself from injury.

He described the attacker as a bearded man between 20 and 30 years old but said it was difficult to tell whether he was Afghan or foreign because his body was badly mutilated.

He said other witnesses told him the bomber had been begging among the crowd.

While the motive for the attack was not immediately clear, Dostum has accumulated many enemies in a career marked by brutality and political opportunism.

A feared commander for Afghanistan's communist government after the Soviet invasion of 1979, he switched to join the mujahedeen rebels as it became clear the regime would fall more than a decade later.

He was a key player in the civil war that destroyed much of Kabul in the mid-1980s, helped U.S. forces oust the Taliban more than three years ago and has been involved in a running feud with ethnic Tajik rivals in the north ever since.

He ran for office in September's landmark presidential elections, coming in fourth thanks to a strong showing in areas populated by fellow Uzbeks, but President Hamid Karzai left him out of his new Cabinet.

The Pakistani truck driver died on Wednesday evening when gunmen opened fire on his fuel truck near the Afghan border town of Spinboldak, district mayor Fazaluddin Agha said. Two others riding in the truck were wounded.

Agha blamed Taliban rebels for the attack on the truck, which was headed for the large U.S. base at Kandahar.