A Pakistani teenager, who took part in an anti-U.S. drone strikes rally in Islamabad last week, was killed in an overnight attack by American spy aircraft in North Waziristan tribal region, a campaigner against the U.S. drone strikes said on Tuesday. Tariq, 16, who belonged to North Waziristan, joined hundreds of tribesmen in a rally in the Pakistani capital on Friday. The demonstrators called for halt to the U.S. strikes, which they said kill civilians. Tariq was killed along with his cousin Waheed, 12, in the U.S. drone strike Monday night near Mir Ali, a main town in North Waziristan, said Karim Khan, who is leading a campaign against the U.S. drone strikes. Khan, from Mir Ali area, had lost his son in a drone attack last year. He has filed a case against the former CIA station chief and several top American officials at a police station in Islamabad for \"murder of innocent tribesmen in drone strikes.\" At least four people were killed in the Monday night strikes on a house and a vehicle, according to correspondents in North Waziristan. It was the forth strike in Waziristan tribal region in five days. On Sunday, a U.S. spy aircraft fired six missiles on a house in North Waziristan tribal area and killed at least six people. At least ten people, including two Taliban commanders, were killed in both strikes in South and North Waziristan on Thursday. The United States has stepped up drone strikes in recent days despite strong opposition by Pakistani government. Pakistan Prime Minister Yusuf Raza Gilani said on Saturday that no permission had been granted to the United States to launch drone attacks on targets inside Pakistan. Gilani, who was in Australia, for the Commonwealth Heads of Government Meeting (CHOGM), told a group of Pakistani expatriates that the drone attacks were counter-productive because they caused collateral damage and undermined the government\'s efforts to garner support against extremists and terrorists. He said the drone attacks were one of the reasons why relations between Pakistan and the United States had deteriorated in recent months. The U.S. spy aircraft routinely fires missiles in the Pakistani tribal regions, claiming that they target suspected al-Qaeda and Taliban militants.