Pakistani military officials say Islamic militants have abandoned a fort they captured near the Afghan border earlier this week.

A military spokesman, Major General Athar Abbas, said Thursday the militants have left the fort at Sararogha town in South Waziristan tribal region.

Several hundred militants attacked the fort with rocket launchers late Tuesday.  The military says at least 40 militants and seven soldiers were killed in the fighting.  Officials are searching for another 15 missing soldiers.

The government says the region is a stronghold for al-Qaida-linked militant leader Baitullah Mehsud, one of Pakistan's most-wanted men.  Officials have blamed Mehsud for the December 27 assassination of former Prime Minister and opposition leader Benazir Bhutto. 

Separately Thursday, militants fired three rockets near a Pakistani air force base in the town of Kamra, north of the capital, Islamabad. Officials say no one was hurt.

Taliban and al-Qaida militants have taken refuge in Pakistan's remote tribal regions along the Afghan border, since the United States ousted the Taliban government in Afghanistan in 2001.

They have repeatedly targeted Pakistani soldiers with suicide attacks, roadside bombs and kidnappings.  Militants abducted 250 troops in South Waziristan in August of 2007.

Pakistani President Pervez Musharraf cited the region's instability and violence as one reason for declaring a state of emergency in November.

Some information for this report was provided by AFP, AP and Reuters.