Taliban militants stopped a bus travelling in southern Afghanistan, captured some 50 people on board and killed around 30 of them, officials said Sunday.

A Taliban spokesman said insurgents killed 27 Afghan army soldiers on the bus, but a local police chief offered a different version of what happened during last Thursday's attack in Kandahar province's Maywand district.

Kandahar police Chief Matiullah Qateh said militants killed one child as they fired on a bus whose driver managed to leave the scene. They stopped a second bus carrying about 50 passengers, killed 24 Afghan civilians who were on board and freed the rest, he said.

It was not possible to reconcile the differing figures. A spokesman for Kandahar's provincial governor said officials would hold a news conference later Sunday.

The Afghan Defence Ministry spokesman, Gen. Mohammad Zahir Azimi, dismissed the Taliban claim that 27 soldiers had been killed.

"Our soldiers travel by military convoy, not in civilian buses. And we have military air transportation," Azimi said.

The general himself reported a higher death toll from the attack. He said 31 people were killed. Six of the dead were beheaded in a separate area of Maywand from where the other 25 bodies were found, according to Azimi.

With files from the Associated Press