The attack took place in the city of Parachinar, near the Afghan border.
It followed overnight clashes between the Pakistani military and pro-Taliban militants at an army checkpoint in North Waziristan, also near the Afghan border.
The Pakistani military said four of its soldiers were killed in that shoot-out.
A military spokesman said 10 militants were killed in the clash overnight south of Miranshah, the main town in North Waziristan, which borders Afghanistan.
Meanwhile, Pakistan says U.S. President George W. Bush has told President Pervez Musharraf that the United States fully respects Pakistan's sovereignty and appreciates Pakistan's resolve in fighting Al-Qaeda and other terrorist elements.
The Pakistani Foreign Ministry said Bush offered the comments in a telephone call with Musharraf.
Pakistan this week objected after U.S. Democratic Party presidential candidate Barack Obama said the United States must be ready to launch possible strikes against extremist targets inside Pakistan if Pakistani forces fail to take action.
(compiled from agency reports)