The bomb, hidden in a donkey cart, exploded in Hasanzai Bazar of Orakzai Agency this morning.
State-run Radio Pakistan reported that six persons were killed and 15 more wounded.
No group claimed responsibility for the attack.
Orakzai Agency is one of the seven semi-autonomous tribal districts of northwest Pakistan.
Islamabad: At least six persons were killed and 15 more injured when a bomb went off in a crowded market in the Orakzai tribal region of northwest Pakistan on Thursday.
First Published: Thursday, October 11, 2012, 12:25