A witness says an explosion has hit a busy market area in the city of Mingora in north-western Pakistan and several people have been injured.
Witness Shiraz Khan says people could be heard crying for help after the blast on Monday afternoon in the Nishat intersection in the city.
Officials did not immediately confirm the report but Pakistani media reported the blast and said casualties were feared.
Mingora is the capital of the Swat district near the Afghan border where a Pakistani military offensive last year pushed out the Taliban after the militants seized control.