Pakistani troops, backed by helicopter gunships and artillery, have begun a ground offensive against pro-Taliban militants in a troubled northwestern valley, killing at least 30 of them, the military said on Sunday. More than 300 people have been killed since October in clashes between troops and militants loyal to a radical Islamist cleric, Maulana Fazlullah, in the scenic Swat valley of North West Frontier Province.

The latest offensive was launched yesterday and troops had taken control of several heights surrounding militant hideouts in the valley. "It's for the first time we have used ground troops in the operation. The operation is continuing and so far 30 militants have been killed," military spokesman Major-General Waheed Arshad said. He said one soldier was killed and two wounded in the clashes. The latest fighting came as militants continued fierce resistance with rockets and mortars against the military push in the adjoining districts of Swat and Shangla. Troops this week cut food supplies to the militants. Violence in Swat, until recently a popular tourist resort, surged after Fazlullah called for a jihad, or holy war, to push his campaign to impose a strict Islamic code in the area. Militants infiltrated from strongholds in the tribal region of North and South Waziristan on the Afghan border to support Fazlullah in recent weeks, while the country's focus was on Islamabad and President Pervez Musharraf's emergency rule.

General Musharraf cited rising militancy as a main motive for declaring the emergency and suspending the constitution, but critics say the real reason was to purge the Supreme Court of judges hostile to him to safeguard his October re-election. On Saturday, at least 17 people were killed in twin suicide attacks near the army's headquarters and a camp of the country's top Inter Services Intelligence agency in the garrison city of Rawalpindi, adjoining the capital Islamabad.