By Qasim Nauman
KAMRA, Pakistan (Reuters) - Islamist militants armed with rocket-propelled grenades and automatic weapons fought their way into one of Pakistan's largest air bases on Thursday, the air force said, in a brazen challenge to the nuclear-armed country's powerful military.
The attack was repelled and only one aircraft was damaged, said an air force spokesman, adding that the Minhas air base at Kamra, in central Punjab province, did not house nuclear weapons.
"No air base is a nuclear air base in Pakistan," he said.
The gun battle raged for hours, and eight militants and one soldier were killed, the spokesman said. Commandos were called in to reinforce base security forces and police armored personnel carriers could be seen heading into the base.
Pakistan's Taliban movement, which is close to al Qaeda and seen as the biggest security threat to the South Asian nation, claimed responsibility for the assault.
"We are proud of this operation. Our leadership had decided to attack Kamra base a long time ago," Taliban spokesman Ehsanullah Ehsan said by telephone from an undisclosed location.
The militants moved through a nearby village under cover of darkness and climbed a nine-foot (2.7-meter) wall strung with barbed wire to break into the base, the air force spokesman said. Some were wearing military uniforms.
The assault cast doubts over official assertions that military operations had severely weakened militants waging a violent campaign to topple the U.S.-backed government and impose strict Islamic rule.
Security forces opened fire when militants strapped with suicide bombing vests approached aircraft hangars, prompting other militants to fire rocket-propelled grenades from outside the base's walls, said the air force spokesman.
Base commander Air Commodore Muhammad Azam, who led the operation against the attackers, was shot in the shoulder but is in stable condition, said spokesman Captain Tariq Mahmood.
Search operations for any other militants who may have been hiding in the complex after the attack had ended, he said.
About an hour later, a series of small explosions could be heard as homemade bombs planted on the base by the militants were detonated by the military.
Minhas, 45 miles northwest of Islamabad, is adjacent to the Pakistan Aeronautical Complex, a major air force research and development center. Pakistan manufactures JF-17 fighter planes, jointly developed with China, at the site.
Suicide bombers launched attacks near the base and the aeronautical complex in 2007 and 2009, but news reports said defenses were not breached.
In Washington, U.S. State Department spokeswoman Victoria Nuland said there had been an improvement recently in cooperation with Pakistan in trying to squeeze militant networks in the region.
"And, you know, it's not -- it's not unusual that when they (the militants) feel squeezed, they lash out. But that just speaks to the necessity of continuing our efforts to end their ability to exact violence on Pakistani citizens, or any of us," she said.
She said she had no information that would contradict Pakistani statements that there were no nuclear weapons at the site.
It was not immediately clear how the attackers managed to enter the sprawling base. Although the attack took place at about 2 a.m. (5 p.m. EDT Wednesday), it is likely many of the soldiers on the base were awake for prayers or breakfast during the holy fasting month of Ramadan.
Faheemullah Khan, a civilian who lives near the base, said he was at a mosque praying when he heard gunfire and explosions that he thought were military exercises.
"Then we came to a restaurant, which is next to the main entrance to the base, and heard a louder explosion," he said.
"We saw six police vans rush in, and realized something was wrong."
Several squadrons of fighters and surveillance planes are believed to be based at Minhas.
"One body of a suicide bomber strapped with explosives has been found close to the impact area," said an air force statement.
Pakistan's Taliban has staged a number of high-profile attacks over the past few years, including one on army headquarters in Rawalpindi in 2009.
Last year, six Taliban gunmen attacked a naval base in Pakistan's biggest city, Karachi, to avenge the killing of Osama bin Laden. At least 10 military personnel were killed and 20 wounded in the 16-hour assault.
Those attacks, and the latest one, are embarrassing for Pakistan's military, which has ruled the country for more than half of its 65-year history and is seen as the most efficient state institution.
The Taliban is blamed for many of the suicide bombings across Pakistan, a strategic U.S. ally.
Pakistan's military, one of the biggest in the world, has staged several offensives against Taliban strongholds in the unruly tribal areas near the border with Afghanistan.
But the operations have failed to break the back of the Taliban. Major suicide bombings have eased considerably over the past year but that could be due to a tactical shift and not pressure from the military. (Additional reporting by Susan Cornwell in WASHINGTON, Sheree Sardar in ISLAMABAD and Jibran Ahmad in PESHAWAR; Writing by Michael Georgy; Editing by Raju Gopalakrishnan and Philip Barbara)