Lahore, Pakistan (CNN) -- Pakistani air force planes swooped down on the country's troubled tribal region on the border with Afghanistan Tuesday, launching a blistering airstrike that left as many as 50 militants dead, Pakistan Army sources said.
The strike in the Miran Shah region was the latest salvo in intense fighting between Pakistani security forces and Taliban and al Qaeda militants that broke out Saturday, as the summer cease-fire crumbled even further.
Those battles -- in North Waziristan, part of the country's largely lawless tribal region -- killed up to 150 militants, as well as 50 government troops, an army spokesman said. Another 20 security forces have been wounded. Intelligence sources said 12 to 15 soldiers remain missing.
According to the army spokesman, the military operation, which was launched Sunday, will continue until peace is completely restored to North Waziristan.
Pakistani officials offered few other details about the scope of the latest fighting which follows recent attacks on Pakistani security forces and a breakdown over the summer of a ceasefire between the Islamabad government and tribal leaders.
That truce was blamed for an increase in attacks on U.S. troops over the border in Afghanistan, as Taliban fighters were able to prepare, train, and reconstitute weapons supplies without interference from the Pakistani government.
The Taliban are the former Afghan regime that sheltered al Qaeda until the U.S.-led war following the September 11, 2001 attacks. U.S. intelligence officials say al Qaeda has established a "safe haven" in Waziristan, just over the border into Pakistan -- and that Osama bin Laden is believed to be in the area.
American and NATO troops pushed the terrorist network and its Taliban allies out of power in Afghanistan following the 2001 terrorist attacks on New York and Washington, but top leaders -- including al Qaeda mastermind bin Laden -- are believed to have found refuge in the mountainous border zone.
Pakistan's president, Gen. Pervez Musharraf, cracked down on al Qaeda militants and arrested many in the Waziristan area before the truce was reached, but critics say he has failed to prevent the militants from gaining strength within the country. E-mail to a friend
CNN's Dan Rivers in Islamabad contributed to this report