A pickup truck packed with a large amount of explosives blew up a security checkpoint in Pakistan's volatile northwest Saturday, killing at least 17 people and injuring nearly 80 in an attack that may have been intended for a more important target, police said. The suicide attack occurred on the outskirts of Peshawar on the day Pakistani lawmakers voted for a new president, underscoring the challenges facing a country the US has pressured to crack down on insurgents. Television footage showed a blast crater three feet deep and destroyed vehicles and pieces of debris scattered across a large area. Officials said many people were trapped under the rubble of damaged buildings in a nearby market. Civilians dug frantically with their hands in hopes of finding survivors. Nasirulmulk Bangash, a top police official in the area, said the vehicle carried at least 330 pounds (150 kg) of explosives – an amount he called “unprecedented” – and was apparently en route to Peshawar. The amount of explosives indicated the attack was aimed at a higher-value target than the small checkpoint, but might have been tripped up by high security on election day, Bangash said, without speculating on what the intended target might have been. Several of the dead were believed to be police manning the post. At Lady Reading Hospital in Peshawar, officials said about 30 wounded people had come for treatment. Meanwhile, Pakistani villagers battled Taleban militants in a northwestern valley on Saturday after the Taleban tried to kidnap a cleric, and 20 villagers and six militants have been killed, police said.