PESHAWAR, Pakistan — Militants detonated two bombs in a busy market and attacked two police checkpoints in northern Pakistan today, killing at least 14 people, wounding scores more and testing the resolve of the government as it takes on the Taliban in the Swat Valley.

The attacks in Peshawar and Dera Ismail Khan happened within two hours of each other and a day after an assault on security forces in the eastern city of Lahore killed around 30 people. That strike was claimed by the Pakistani Taliban, which warned of further attacks unless the government called off the Swat offensive.

"Our targets are security forces, who are killing innocent people in Swat and other adjoining areas," said Hakimullah Mehsud, a deputy to Pakistani Taliban chief Baitullah Mehsud. "We regret that some innocent people were also killed in the Lahore attack, we did not want that."

Two bombs in Peshawar were mounted on motorcycles and exploded within seconds of each other, tearing off walls and shattering windows of a row of small shops at a popular market, police and witnesses said.