PESHAWAR, Pakistan (Reuters) -- Pakistani helicopter gunships have attacked Taliban positions in the South Waziristan region on the Afghan border, killing six militants, intelligence officials and residents said.
The attack came as the army pressed on with an offensive against the Taliban in their Swat Valley bastion, about 350 kilometers to the northeast of South Waziristan, in its most concerted attempt to push back an expanding insurgency.
Speculation has been mounting that the army would soon turn its attention to South Waziristan, the headquarters of Pakistani Taliban leader Baitullah Mehsud and a major base area for his Afghan Taliban allies battling Western forces in Afghanistan.
The army sent in its helicopters shortly after militants fired rockets at a paramilitary force base in the town of Siblatoi, 60 kilometers east of Waziristan's main town of Wana.
"The helicopter gunships are still attacking and so far six militants have been killed and 14 wounded," said an intelligence agency official in the area said, adding that ground troops had secured the nearby village of Chakmali.
South Waziristan has been a militant hub for years.
Many Taliban and Al-Qaeda fighters fled there, and to neighboring North Waziristan, after U.S. forces and their Afghan allies drove the Taliban from power in Afghanistan in the weeks following the September 11, 2001, attacks on the United States.
The United States and Afghanistan's U.S.-backed government have long pressed Pakistan to do more to root out militants from their border strongholds.
The United States, which is pouring thousands of extra troops into Afghanistan this year, has been attacking militants in both South and North Waziristan with missile-firing drone aircraft.
Tension has been building in South Waziristan since President Asif Ali Zardari told Britain's "Sunday Times" newspaper just over a week ago that the military would move against militants in Waziristan after clearing Swat.
Though Zardari is reported to have later denied that, military officials say an all-out offensive against militants in South Waziristan looks inevitable.
"We're ready for an operation in South Waziristan. Now it's
just a matter of time," a senior intelligence official said.
Military spokesman Major General Athar Abbas said last week there would be an operation in Waziristan and its timing would depend on the national interest.
With tension rising, civilians have begun leaving. Authorities are already trying to help more than 2 million people displaced from Swat and nearby districts.
About 10,000 people have fled from South Waziristan in recent days, many to the town of Dera Ismail Khan on the lowland to the east, a senior government official said.
"Now they're staying with relatives in Dera Ismail Khan and other areas but if the situation worsens then we'll have to make arrangements for their shelter and needs," said the official.
South Waziristan resident Mir Nawaz said he wasn't waiting for the fighting to start in earnest before getting his wife and children out.
"We're leaving our home because civilians die more than anyone else in such operations. I don't want my children to be killed," Nawaz said by telephone.
Authorities have accused Pakistani Taliban leader Mehsud of being behind a wave of attacks over the past two years, including the 2007 assassination of former Prime Minister Benazir Bhutto.
The United States announced in March a reward of $5 million for information leading to his location or arrest.