KANDAHAR, Afghanistan >> A police truck packed with officers and detainees struck a roadside bomb in southern Afghanistan’s largest city, killing 10 of those aboard, officials said today.

It was one of four blasts Saturday that left at least 24 people dead across the country. Attacks by insurgents are a daily occurrence around Afghanistan and the Afghan police with their unarmored pickup trucks and remote checkpoints are a common target.

In the Kandahar city blast, police had driven to a residential neighborhood of the city at night to inspect a bomb that had been found there, said Javid Faisal, a spokesman for the provincial government. They detained three suspects and were driving back with them in a police pickup truck when the vehicle struck another explosive buried in the road. Eight police officers and two detainees were killed in the blast.

Meanwhile, Afghan authorities accused NATO of killing three civilian men in a nighttime ambush in the eastern Logar province. The coalition disputed the account, saying it had no operations in Logar’s Baraki Barak district Saturday night. NATO said there were three dead, but they were insurgents killed by Afghan forces.

Deputy provincial police chief Rais Khan Abdul Rahimzai said all three of the added were civilians. “They were brothers. They had dinner at one of their brother’s houses in another part of the district and it was when they were driving back that they were ambushed by the foreign soldiers,” Rahimzai said. “It was a misunderstanding in which foreign forces shot and killed three people.”

A spokesman for the international force disputed the Afghan version of the incident. “This was the ANSF,” said Maj. Martyn Crighton, referring to the Afghan National Security Forces. He said they went after three men who had been seen burying a bomb in the ground and “got engaged in a firefight with these guys.”

It was not possible to reconcile the conflicting accounts.

Earlier Saturday, 10 policemen were killed when a suicide bomber on a motorcycle blew himself up in Kunduz province in the north. Elsewhere, a remote-controlled bomb planted on a bicycle exploded in the eastern city of Ghazni, killing one police officer and a civilian. And in the west, officials in Farah province said Sunday that two police officers were killed there Saturday evening when their vehicle hit a roadside bomb.

On Sunday in the south, a roadside bomb in the town of Marjah killed another three police officers, said Ahmad Zarak, a spokesman for the Helmand provincial government.