A bus in southern Afghanistan was hijacked last week by the Taliban.
As many as 40 passengers are reported to have been killed - although only six beheaded bodies have been recovered so far.
Kandahar provincial police chief Mutihullah Khan Qatah said there were 50 passengers aboard the bus when it was ambushed on Thursday in Maiwand district about 50km east of Kandahar city. Ten civilians were released.
The Taliban says 27 passengers were killed because they were soldiers. The defence ministry denied any troops were on board.
About 150 labourers were kidnapped in the western province of Farah late last month, also while travelling by bus.
They were carpenters, masons and other labourers employed by a US construction company on a project for the Afghan National Army.
Authorities said they were all freed about a week later.