At least seven people were killed in two separate US drone attacks in North Waziristan tribal district on Sunday, officials said. "The US drone hit a car immediately after it parked outside a house. Four militants have been killed," an intelligence official in Miranshah told, adding that the vehicle was completely destroyed and the house badly damaged. A second intelligence official said the drone fired two missiles. The unmanned aircraft launched the missiles in Datta Khel, some 40 kilometres (25 miles) west of North Waziristan's main town of Miranshah. A second US missile attack killed at least three suspected militants, local officials said. The latest strike is the ninth of its kind since the start of this year. On Jan. 1, a string of four drone attacks in North Waziristan killed about 19 people. In a rare show of strength, thousands of tribesmen on Friday marched in Miranshah, the center of North Waziristan, against the U.S. drone strikes, which they said killed innocent people and disrupted their lives. Since 2010, the United States has apparently stepped up drone strikes in North Waziristan. Government publicly criticizes the U.S. drone strikes but it is widely believed that there is understanding between the two countries. The Pakistani government denies any understanding.