More than 30,000 Pakistani soldiers launched a ground offensive against al-Qaeda and the Taliban's main stronghold along the Afghan border yesterday in the country's toughest test yet against a strengthening insurgency.

The US pushed the government to carry out the assault in South Waziristan and it comes after two weeks of militant attacks which left more than 175 people dead.

Pakistan has fought three unsuccessful campaigns since 2001 in the region, which is the nerve centre for Pakistani insurgents fighting the US-backed government. It is also a major base for foreign militants planning attacks on American and Nato forces in Afghanistan and on targets in the west.

After months of aerial bombing, troops yesterday moved into the region from several directions, heading to the insurgent bases of Ladha and Makeen among other targets, intelligence and military officials said. The operation was expected to last around two months.

Pakistani army spokesman Major General Athar Abbas confirmed that a fully-fledged ground operation was under way, and said it aimed to "uproot" the Pakistani Taliban. He said it was too early to discuss what sort of resistance the army was meeting.

The United Nations has said it is preparing to help civilians fleeing the region. Up to 150,000 civilians have already left in recent months after the army made clear it was planning an assault, but as many as 350,000 remain.

The army has deployed more than 30,000 troops to the region, said one of the intelligence officials. The military has already said it has sealed off many supply and escape routes and has been trying to secure the support of local tribesmen in the fight.

Speaking earlier in the week, Abbas said the assault would be limited to slain Pakistani Taliban leader Baitullah Mehsud's holdings – a swathe of territory that stretches roughly 1,275 square miles. That portion covers about half of South Waziristan.

The plan is to capture and hold the area where Abbas estimates 10,000 insurgents have their headquarters, reinforced with about 1,500 foreign fighters.

Despite sometimes rocky relations with the Pakistani military, the US is trying to rush in equipment for the offensive that would help with mobility, night fighting and precision bombing, a US embassy official said. The Pakistan military has said it is also seeking additional Cobra helicopter gunships, heliborne lift capability, laser-guided munitions and intelligence equipment to monitor cell and satellite telephones.