PESHAWAR At least 17 suspected militants were killed and five others got injured on Tuesday when US drones targeted different areas in North Waziristan Agency. According to sources, the drones fired 18 missiles in different areas of North Waziristan including Muhammad Khel, Khar Qamar, Deggan and Miranshah. It is feared that number of casualties may increase, as the spy planes were hovering in the area till filing of this report. On the other hand, the tribesmen were continuously firing to hit the predators. Agencies add: US drones fired 18 missiles into a Pakistani sanctuary for Al-Qaeda and Taliban fighters on the Afghan border on Tuesday, killing at least 17 people and injuring five others, residents and security officials said. The United States has stepped up drone strikes on militant sanctuaries on the Pakistani side of the Afghan border since a December 30 suicide bombing killed seven CIA employees at a US base in the eastern Afghan province of Khost. The latest drone attack, the 13th this year, was the heaviest ever in terms of the number of missiles fired. The US aircraft targeted several militant compounds in the North Waziristan ethnic Pashtun border region. Up to eight US drones fired some 18 missiles at multiple militant targets in Dattakhel village, a senior security official told AFP. The death toll for now is 17 but it could be more. Fire is still raging where the missiles struck, a Pakistani security official was quoted as saying. Two vehicles belonging to the militants were also destroyed in the strike on the village, 30km west of North Waziristans main town of Miranshah, said another security official who also declined to be identified. Local administration and intelligence officials confirmed the deaths after the volley of strikes reportedly struck militant hideouts and a training centre in three places in the village. Residents in Miranshah said that they saw the drones flying overhead and heard the explosions from the village. Dattakhel is a stronghold of Hafiz Gul Bahadur, a Taliban commander who is believed to be harbouring and sending militants across the border to fight Western forces in Afghanistan. The US sees the elimination of suspected militant enclaves in the tribal region as vital for bringing stability to Afghanistan. But the drone strikes are a source of friction with Pakistan, which says they are a violation of its sovereignty. Islamabad has demanded that the US provide it with drone aircraft so it can hit militants on its own. US officials say the missile strikes are carried out under an agreement with Islamabad that allows Pakistan leaders to decry the attacks in public. Pakistan denies this.