An Afghan official says a bombing in the northern Kunduz province has killed 22 members of illegal armed groups, including four leaders.

Abdul Wadood Wahidi, spokesman for the provincial governor, said the bombing late Saturday targeted a meeting of criminal groups that in the past have clashed with both national security forces and Taliban insurgents.

He said seven others were wounded by the blast in Khan Abad district.

Taliban spokesman Zabihullah Mujahid claimed the attack.

The Taliban have stepped up attacks across the country since U.S. and NATO forces shifted from a combat to a support and training role at the end of last year.