At least 38 militants were killed in fierce clashes in northwest Pakistan's Swat valley and the tribal region of South Waziristan, the military said Saturday as troops continued an offensive against the Taleban. “During (the) last 24 hours, 38 militants were killed in Malakand and South Waziristan, while six soldiers including an officer embraced martyrdom,” it said in a statement. Malakand region includes Swat, Dir and Buner districts where the military has launched operations since April 26 against Taleban militants. The death tolls provided could not be verified independently. “Thirty-two terrorists were killed in Sarwakai town (in South Waziristan) in a retaliatory fire by security forces during a road clearance operation,” the statement said. The rugged South Waziristan region is the stronghold of Pakistan Taleban chief Baitullah Mehsud, and Washington alleges that Al-Qaeda fighters who fled Afghanistan after the 2001 US-led invasion are holed up in the region. Pakistani war planes Friday hit targets in South Waziristan, apparently in preparation for a full-scale military onslaught into the hostile peaks to track down and eliminate Mehsud and his network. Pakistan's semi-autonomous tribal regions are wracked by violence and are known as a hub for Taleban and Al-Qaeda rebels who fled across the border to escape the US-led invasion of Afghanistan in late 2001. Six other militants “were killed in an exchange of fire with security forces,” in Swat valley, the military said. It added that 17 soldiers were also wounded during clashes with militants in Malakand. More than 1,500 insurgents and 134 soldiers have been killed in military operations launched in Lower Dir on April 26, Buner on April 28 and in Swat on May 8. Pakistani security forces launched the offensive to dislodge Taleban guerrillas from the three districts after rebels flouted a peace deal and thrust towards the capital Islamabad. The government has slapped a $600,000 price on the head of firebrand Swat Taleban commander Maulana Fazlullah, wanted dead or alive, for masterminding the nearly two-year uprising in the valley to enforce Shariah law. About 2 million people have fled the fighting in northwest Pakistan. The exodus grew with the start of the campaign in Swat and nearby Buner district and the prospect of more people abandoning their homes with new fighting in Waziristan will add to fears of a humanitarian crisis. Hundreds of those uprooted by the fighting in Buner headed back to their homes on Saturday after authorities urged them to return to secure areas. Officials said that would help build confidence and contribute to the defeat of the Taleban. Cars packed with people and their belongings were seen moving in bumper-to-bumper traffic on the road into Buner from Mardan, where the government and aid agencies have set up tented villages for the displaced.