Security was tight on Friday in the tribal area around Dila Khula, where the military said it had smashed a foreign "terrorist training camp" on Thursday.
Checkpoints were thrown up on roads around the nearby town of Wana and access to the main market was blocked.
In one of the bloodiest assaults yet on foreign fighters and local tribal allies, jets and helicopters on Thursday pounded the suspected training camp 25km north-east of Wana, the main town in the South Waziristan tribal region.
Fighters, civilians killed
Military officials said 50 fighters had been killed, while witnesses said many civilians also died in the fighting.
"According to our information some 50 miscreants, mainly foreign militants, were killed in the air attack and if there were any locals, they were their supporters or facilitators," Major-General Shaukat Sultan said in Islamabad.
Various reports from the region's administrative capital of Wana suggested the toll could be as high as 70 and included civilians.
"We made maximum efforts to avoid any collateral damage and no civilian areas were targeted," Sultan said.
Local residents said sporadic firefights between security forces and suspected fighters continued throughout the night in different parts of the region, but there were no immediate reports of casualties.
Pakistan has sent 70,000 troops to the tribal belt bordering Afghanistan and has fought a series of fierce battles with rebels it says are Islamist fighters - including foreigners from the Middle East, Uzbekistan and Chechnya this year.
Many al-Qaida operatives and their local partners caught in a swoop against the network in recent months, have been operating in tribal areas, and officials say assassination attempts on leading political and military officials are planned there.
Pakistan has sent 70,000 troops
to the belt bordering Afghanistan
Al-Qaida and its allies are furious at Pakistani President Pervez Musharraf's decision to back the US-led "war on terror", and have been blamed for two attempts on his life late last year as well as unsuccessful attempts to kill the prime minister and an army corps commander in Karachi.
The foreign fighters in Pakistan's tribal belt, many of them there since the end of the US-funded insurgency against the Soviet occupation of neighbouring Afghanistan, enjoy strong support from local tribesmen.
Others fled into Pakistan from Afghanistan when the US military toppled the Taliban after the 11 September 2001 attacks blamed on Usama bin Laden's al-Qaida.
Officials on Friday bulldozed the shops of a suspected tribal sympathiser in Wana in a traditional form of punishment in the deeply conservative region.
"Punitive action is taken against anyone breaking the law"
Maj-Gen Shaukat Sultan,
Pakistan army spokesman
"Punitive action is taken against anyone breaking the law," said Sultan.
"Punitive action means people can be sent to prison, their house or shop can be demolished. This all is done by the political administration," he told private Geo Television.