More than 30,000 Pakistani soldiers launched a much-awaited ground offensive in an al-Qaida and Taliban stronghold along the Afghan border early Saturday, officials told The Associated Press - the nuclear-armed US ally's toughest test yet against militants aiming to topple the state. The offensive in South Waziristan follows months of airstrikes intended to soften up militant defenses that have also forced tens of thousands of civilians to flee. The full-scale operation also comes after two weeks of militant attacks that have killed more than 175 people and ramped up the pressure on the army to take on the insurgents. Aside from being the nerve-center for Pakistani insurgents opposed to the US-backed central government, South Waziristan is a key base for foreign and national jihadi groups planning attacks on American and NATO targets in Afghanistan and beyond. The US is racing to send in night-vision goggles and other equipment to aid the latest operation. The region is remote and mountainous. It has a leaky border with Afghanistan and fiercely independent tribes who have long resisted government interference. With winter snows just weeks away, the army has limited time to pursue a major ground attack there, and even if it does manage to wipe out its intended targets, it's unclear whether troops will occupy the area or for how long. Even if the operation is largely successful in South Waziristan, many of the militants could escape to Afghanistan or other parts of Pakistan's semi-autonomous tribal belt. The officials Saturday - two with intelligence, three with the government and one senior army official - gave few details but said the troops were pursuing militants holed up in the region, including in major trouble spots such as Ladha and Makeen towns. The army has sent more than 30,000 troops to the region to participate in the combat, said one of the intelligence officials. He said the ground forces were attacking from different directions while helicopter gunships and other aircraft also were bombing various sites. The military already has said it already has sealed off many supply and escape routes. All the officials spoke on condition of anonymity because of the sensitivity of the information or because they did not have authority to release it to media on the record. It is nearly impossible to verify information from the region independently. Foreigners require special permission to enter tribal areas and many Pakistani journalists from other parts of the country are at risk there. The army has tried three times since 2001 to dislodge Taliban fighters from South Waziristan. All three previous attempts ended in negotiated truces that left the Taliban in control. This time the military has said there will be no deals, partly to avoid jeopardizing gains won earlier this year when Pakistani soldiers overpowered the Taliban in the Swat Valley, another northwest region. In a previous interview with AP, army spokesman Maj. Gen. Athar Abbas said the assault would be limited to slain Taliban leader Baitullah Mehsud's holdings - a swath of territory that stretches roughly 1,275 square miles (3,310 square kilometers). That portion covers about half of South Waziristan, which itself is slightly larger than the US state of Delaware. The plan is to capture and hold the area where Abbas estimates 10,000 insurgents are headquartered and reinforced with about 1,500 foreign fighters, most of them of Central Asian origin. "There are Arabs, but the Arabs are basically in the leadership, providing resources and expertise and in the role of trainers," he said. Taliban spokesmen could not immediately be reached for comment Saturday. Communications in and around the region appeared jammed, making it difficult to reach local residents or other witnesses. The army expects the militants to use guerrilla tactics including ambushes, suicide attacks and roadside bombs. A roadside bomb hit a security convoy in Ladha early Saturday, killing one soldier and wounding three others, two other intelligence officials said. Despite sometimes rocky relations with the Pakistani military, the US is trying to rush in equipment that would help with mobility, night fighting and precision bombing, a US Embassy official told The Associated Press in a recent interview, speaking on condition of anonymity because the issue is politically sensitive. In addition to night-vision devices, the Pakistan military has said it is seeking additional Cobra helicopter gunships, heliborne lift capability, laser-guided munitions and intelligence equipment to monitor cell and satellite telephones. The army has considered the weather in the timing the offensive. Snows in the region could block major roads. At the same time, a harsh winter could work to the army's advantage by driving fighters out of their unheated mountain hideouts. Amnesty International said Friday that its research teams in the area report 90,000 to 150,000 residents have fled South Waziristan since July, when the military began a long-range artillery and aerial bombardment in the region. Although the military has been hitting targets in South Waziristan for the past three months, it waited until two weeks ago to say it would definitely go ahead with a major ground offensive into the region. What followed was a rash of major bombings that killed 175 people and demonstrated the militants' ability to attack cities across the county. One attack involved a siege of the army's headquarters that lasted 22 hours and left 23 people dead. In the latest bombing, three suicide attackers, including a woman, struck a police station in the northwestern city of Peshawar on Friday, killing 13 people.