The latest blast in a week of violence that has claimed more than 200 lives came as the United States ramped up pressure on Musharraf to hunt down al-Qaeda and Taliban militants -- and threatened to go it alone if he fails to do so.

Musharraf, under pressure from all sides, also faced a court decision key to his political future, with a panel due to rule on his battle against the chief judge he ousted in March, who has since become a pro-democracy icon.

The latest suicide attack hit the tribal area of North Waziristan, as government officials and Pashtun elders met in a secret location to salvage a ceasefire accord that pro-Taliban militants there scrapped this week.

"A suicide attack on a paramilitary checkpost in North Waziristan killed four people -- three civilians and one soldier," chief military spokesman Major General Waheed Arshad told AFP. A gunbattle broke out after the blast.

Musharraf has vowed to hunt down al-Qaeda and Taliban fighters allegedly hiding in Pakistan's rugged areas on the Afghan frontier, according to the United States and Nato forces in war-torn Afghanistan.

The military ruler -- who sparked Islamist rage by ordering troops to storm a pro-Taliban mosque in Islamabad last week -- gathered key officials for an emergency meeting, focused on restoring order in the battle-torn northwest.

Prime Minister Shaukat Aziz, the governor of North West Frontier Province and other key officials were attending the talks at the president's army residence in Rawalpindi, a presidential spokesman told AFP.

"The participants will exchange views on the law and order situation in the wake of the recent bomb blasts, and discuss measures to control the situation and bring peace," the spokesman said.

The meeting came after the White House ramped up the pressure on its key ally.