Aljazeera's correspondent in Islamabad quoted tribal sources on Thursday saying Pakistani forces bombed areas where they believed foreign and tribal residents were holding a meeting in South Waziristan.
Sources said the number of dead are in the tens.
Army officials said there were "many" casualties from Thursday's bombardment, but the exact number were not certain.
Pakistan's Geo television said the dead and injured in the assault near the border with Afghanistan could reach as high as 50.
An unnamed Pakistani army official said the targeted area was a training ground for foreign fighters. But the military had no immediate official comment.
Pakistan has frequently overstated the scope of its military operations, claiming to have captured or killed foreigners that turn out to be local tribesmen, or to have zeroed in on top al-Qaida men who never materialise.
However, a large number of Central Asian and Arab fighters are believed to be living in the tribal areas. Many came to fight alongside US-backed Afghan mujahidin against the Soviet Union in the 1980s, and never left.
Geo television reported that a missile struck a compound near Khunkhela village, just northeast of the main town of Wana, early on Thursday. It said foreign and local fighters were believed to be at the site, and dozens may have been killed or wounded.
Alam Khan, a resident of Ladha, a village near Khunkhela, said that three other nearby villages were also hit in the operation. He also said that he saw at least two jets and about 10 army helicopters flying over the scene during the fighting, which lasted about two hours.
Dust and smoke could be seen rising from houses in the villages, Khan said. He was unsure about casualties.
Pakistani soldiers in action in the
South Waziristan town of Wana
Pakistan's army has launched frequent attacks in North and South Waziristan against suspected Taliban fighters. The area is considered a possible hideout for Usama bin Ladin, though there is no hard evidence of his whereabouts.
The bombing came after a landmine injured three soldiers in Wana on Wednesday, prompting a firefight that left seven tribesmen dead, an intelligence official said on Thursday.
Later, a rocket landed in a field near a military base, but there were no injuries.
Pakistan, an ally of the US, has deployed tens of thousands of troops along the Afghan border to fight al-Qaida and Taliban fighters operating there.
The military said that troops had come also under gunfire after the landmine attack, but residents accused the troops of firing indiscriminately at civilians.
About 50 people were rounded up in an effort to find out who planted the mine, and 28 were still being held for questioning on Thursday, the military said.