At least seven people have been killed in a bomb blast in a market in Pakistan. It is the latest in a series of attacks, as the government battles an insurgency be Islamic militants.Around 50 people are said to have been injured in the explosion in the northwestern city of Dera Ismail Khan. Elsewhere in the region, three suspected militants were killed in a missile attack reported to have been carried out by a US drone aircraft. Pakistani is struggling to put down an insurgency by the Taliban. Security forces have made progress in the Swat Valley. But they have responded with a wave of bomb attacks.