At least 42 suspected Taliban and al-Qaeda members have been killed as the Pakistani military continued its push into South Waziristan, military officials have said. 

The fighters were said to have died in some of the heaviest clashes since an estimated 30,000 troops were deployed 11 days ago to tackle the Tehreek-e-Taliban Pakistan (TTP) in the semi-autonomous tribal region.

Security forces were said to have surrounded Nawazkot, a purported Taliban stronghold, and fighters were killed in clashes on the approach to Sararogha to the east and Kanigurram further south.

Warplanes and helicopter gunships bombarded positions believed to be used by the estimated 12,000 fighters believed to operating in the region, the military said on Tuesday.

The latest casualties put the total number of fighters claimed killed in the offensive at 239. At least 31 soldiers have also died, the military said.

The figures given by the military are impossible to verify as journalists and aid workers are barred from the conflict zone.   

Civilian suffering

The army has claimed that the offensive is making progress following the capture of Kotkai, the hometown of Hakimullah Mehsud, a Pakistani Taliban leader, on Saturday. 

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But footage obtained by Al Jazeera showed that civilians were paying a high price for the military gains.

Residents of Kotkai could been seen picking through the rubble of their homes, while in the nearby town of Wana the main hospital had been overwhelmed by casualties.

More than 125,000 people have been registered as displaced by the fighting since October 13, UN officials have said.

"They join the other 80,500 people which were previously registered. So this means the total registered caseload in terms of families is 28,242, which is around 206,000 people," Arianne Rummery, a UN refugee agency spokeswoman, said.

Meanwhile, a Pakistani army brigadier narrowly escaped an attack in the capital, Islamabad.

"Brigadier Waqar Ahmed, who was posted at GHQ [general headquarters], was accompanied by his mother and driver and was  going to a local hospital when terrorists fired bullets on him," Khurshid Khan, a police officer, told the AFP news agency.

"Luckily all of them survived."

Muhammad Imran, who runs a business nearby, said he saw a young man take out a weapon from beneath his shawl and unleash a hail of bullets as the car slowed down for a speed bump.

"He was firing relentlessly. He was targeting the front seat of the car," Imran said.

Another young man on a motorcycle then appeared and the two sped away.

Last Thursday, armed men on a motorcycle fired on an army vehicle in another part of Islamabad, killing a brigadier and a soldier in what was believed to be the first assassination of an army officer in the capital.

More than 200 people have been killed this month in attacks blamed on pro-Taliban fighters. 

Source: Al Jazeera and agencies