A missile killed six Taleban fighters in northwest Pakistan on Tuesday, intelligence officials said, apparently the latest strike in a covert US program that American officials are considering intensifying. US drones have carried out more than 70 missile attacks in the north over the last year, but the strikes are rarely acknowledged by Washington. The United States says the mountainous tribal belt along the border is a base for militant attacks on American and NATO troops in neighboring Afghanistan and a stronghold of Al-Qaida's senior leadership.An unmanned US drone targeted a Taleban compound in the South Waziristan tribal region and killed six insurgents, including two Uzbek fighters, and wounded six others, two Pakistani intelligence officials said on condition of anonymity because they were not authorized to release the information. The missile attack occurred in Sararogha village, the base of former Pakistani Taleban chief Baitullah Mehsud, who was killed in an Aug. 5 strike by an American drone. South Waziristan is an al-Qaida and Taleban stronghold that has seen a spike in violence in recent days, including suicide attacks and rocket and mortar exchanges between militants and the Pakistani army. The army has moved into other areas in the northwest over the last year, but has so far avoided major operations in Waziristan. The US missile attacks have killed several al-Qaida and Taleban commanders as well as civilians. The Pakistani government routinely protests the attacks, but they are widely believed to take place with the sanction of Pakistani security agencies. Washington says defeating the militants in Pakistan is vital for stabilizing Afghanistan, where violence is raging eight years after the US-led invasion to topple the Taleban. The US believes much of the Afghan insurgency is directed by militants in safe havens across the border. - AP U.S. officials have said they are considering a strategy of intensified unmanned drone attacks against al-Qaida and Taleban targets on the Pakistani side of the border, as an alternative to sending more troops to Afghanistan. Pakistani soldiers traded rocket and mortar fire with militants as hundreds of civilians fled the Taleban and al-Qaida's main stronghold in the northwest. Residents said the military and the Taleban had urged them to flee South Waziristan in recent days.