An Afghan official says a woman detonated her explosives' vest at a checkpoint in eastern Nangarhar province, killing her three children and an officer who stopped their suspicious-looking car.

Attaullah Khugyani, the provincial governor's spokesman, said Friday the attack happened late Thursday in the provincial capital of Jalalabad.

An Afghan security official says officers from the NDS intelligence service stopped the car with the woman, her children and four men at the checkpoint.

The woman and the children got out. The official says they couldn't the Afghan languages of Pashto and Dari and appeared to be speaking Russian. The official spoke on condition of anonymity because he isn't authorized to talk to reporters.

It's unclear what happened to the men in the car.

Afghanistan's war has long attracted foreign fighters.