MIR ALI, Pakistan — A suspected U.S. missile strike killed 13 people Saturday in a Pakistani tribal region where several militant outfits plot attacks on Western troops across the border in Afghanistan, officials said.

The missile, apparently fired from an unmanned drone, struck a house in Haider Khel village near North Waziristan's Mir Ali town, said two intelligence officials who spoke on condition of anonymity because they were not authorized to speak to media on the record.

Local government official Noor Mohammad said at least 13 people had been killed, while the intelligence officials said some foreigners were among the dead. Their exact identities and nationalities were not immediately clear.

A roadside bomb aimed at police elsewhere in the country's volatile northwest killed a civilian and wounded eight people. Also, gunmen opened fire on police at a court in the southern city of Karachi; one police officer and an attacker were killed.

The attacks came as U.S. special envoy Richard Holbrooke met with Pakistani leaders in Islamabad, the latest in a series of visits aimed at shoring up Pakistani support for the American effort in Afghanistan.