UP TO 20 hardliners were believed to have been killed as Pakistan military forces hit Taliban positions in the inhospitable mountain district of South Waziristan for a second day running yesterday.After months of planning the military began a big ground offensive against insurgents from Tehrik-e-Taliban Pakistan – or Pakistan Taliban – in the lawless region bordering Afghanistan on Saturday.A force of about 30,000 troops was massed for the campaign backed by tanks, artillery, fighter jets and helicopter gunships. It is the biggest operation by the Pakistan military in six years.Government forces face as many as 12,000 Taliban fighters in South Waziristan who were reported to be offering stiff resistance in the face of the military’s onslaught.Pakistani forces pounded Taliban hideouts with artillery fire yesterday after advancing on three fronts. Between 17 and 20 militants had been killed so far in the operation, officials said.The Pakistan military confirmed that four soldiers were killed and 12 badly injured on the first day of fighting. Two soldiers died and four were injured in a gun battle with Taliban fighters at Mandana, and two more troops died during an exchange of fire at Saidullah.An army spokesman, Major-General Athar Abbas, said: ”The operation will continue until the objectives are achieved. The army has blocked all entry and exit points of Waziristan.”The army has a window of about six to eight weeks to make significant advances before the onset of a biting winter and snow. The campaign was opened at the end of a bloody fortnight in Pakistan in which more than 170 people were killed in a wave of terrorist strikes. The Pakistan Taliban, led by Hakimullah Mehsud, claimed responsibility for most of the attacks.The country’s big cities are on high alert in the fear that the Taliban could carry out revenge over the campaign.Hours before the offensive began, the Prime Minister, Yousuf Raza Gilani, put out a statement saying ”the national consensus is reaffirmed to establish and maintain the writ of the state to weed out these elements”. The ground operation follows weeks of air strikes against militant targets in South Waziristan.In May the army staged a successful campaign against the Taliban in the Swat Valley of North West Frontier Province. But military analysts have warned that beating the Taliban in South Waziristan will be a much bigger challenge.The army faces an experienced and motivated enemy, and the mountainous terrain will make transport and intelligence gathering difficult.About 90,000 civilians have fled South Waziristan, normally home to 600,000 people, since August. A Pakistani Army official said: ”We estimate that around 100,000 more people can be displaced, say a total of around 150,000 to 200,000 people.”In addition to the estimated 10,000 to 12,000 fighters from the Pakistan Taliban in South Waziristan, there up to 25,000 across Pakistan’s semi-autonomous tribal belt, which has a history of fierce independence.with agencies