ISLAMABAD, Pakistan — Fears for Pakistan’s stability intensified last night after Islamic fighters ended a fragile peace agreement amid a wave of bloody attacks against security forces.

Pro-Taliban militants in the North Waziristan tribal area on the Afghan border called off the 10-month peace deal with the government after accusing authorities of violating the pact.

More than 30 people were killed in suicide attacks in the northwestern region of the country yesterday. The deaths brought the number of members of the Pakistani security forces killed over the weekend to more than 50. It followed the commando assault on the radical Lal Masjid mosque in Islamabad, the capital, last week.

At least 102 people died in the weeklong siege included 11 soldiers and an as yet unknown number of extremists and their hostages.

The end of the deal is a blow to President Musharraf. The Pakistani army had agreed to withdraw from the region and turn all control over to tribal elders. In return, Taliban and Al Qaeda forces sheltered in Waziristan were supposed to stay out of Afghanistan. Military operations on the frontier had claimed the lives of 600 Pakistani soldiers and were a powerful source of opposition among both civilians and the armed forces to the military leader. American commanders and senior White House officials had repeatedly expressed doubts about the deal.

The government faces a rapidly deteriorating security situation in North West Frontier Province, one of the country’s four provinces. Fourteen people, 11 of them paramilitary soldiers, were killed in a suicide-bomb ambush on a patrol in the scenic Swat valley early yesterday. Hours later, a suicide bomber targeted a police recruiting center in the city of Dera Ismail Khan, in the same province, killing 14, most of them young men taking a police entrance exam.

“The attacks in Swat and D I Khan could be linked to the Lal Masjid,” said Aftab Ahmed Sherpao, the interior minister, who recently survived a suicide attack. “It’s very difficult to stop suicide attacks.”

More than 70 security forces personnel have been killed in bombings and shootings since the mosque crisis began 12 days ago. Clashes between security forces and militants in the ethnically Pushtun NWFP risk being transformed into a low-intensity insurgency comparable to the one being waged against American-led forces by Pushtun Taliban in Afghanistan.

Thousands of troops were deployed across the frontier province over the weekend. An army brigade was reportedly sent to the province’s Swat Valley, where a suicide car bomber also killed three policemen last week.

Security officials fear that Swat, which is in thrall to a radical militant cleric, Maulana Fazlullah, will be the next flashpoint.

The government has suggested that there were links between Al Qaeda militant groups based in NWFP and the Lal Masjid.

It was reported that unnamed officials had claimed that soldiers who took control of the Islamabad mosque discovered letters from Osama bin Laden’s deputy, Ayman al-Zawahri.

A draft of a new American intelligence report leaked to the press last week claimed that Al Qaeda is at its strongest since just before the September 11, 2001, attacks. Mr. bin Laden appeared in a video clip released on a militant Web site over the weekend. The brief and undated film did not appear to have been shot recently and did not refer to contemporary events.