There were conflicting reports about casualties following a bomb attack on a US consulate vehicle in the Pakistani city of Peshawar.
Two US personnel and two Pakistani staff of the consulate were injured in the blast, according to the US embassy.
However, Regional Information Minister Mian Iftikhar Hussain said that at least four people, including two Americans, were killed.
There was no immediate claim of responsibility for the attack, which left a crater along a busy street.
Firemen could be seen putting out a vehicle that was mangled and blackened from the explosion.
Television stations repeatedly broadcast an image of a US passport at the scene, its corners scorched by fire.
Pakistan's Taliban, who are close to al-Qaeda, are blamed for many of the suicide bombings across Pakistan, a strategic US ally.
Those attacks had eased in recent months but it was not clear if the lull was due to pressure from military offensives or a shift in tactics.
