QUETTA: An American aircraft arrived in Pakistan on Sunday for US nationals vacating the Shamsi airbase in Balochistan, DawnNews reported. Strict security measures were being taken place in the area and residents were told not to leave their homes. According to sources, the process of shifting the US nationals into to the aircraft had started already. The road leading towards the airport had also been sealed for security purposes. Pakistan had demanded that the US leave the airbase used for drone flights within 15 days of the Nato attack in Mohmand Agency on November 26 that left 24 Pakistani soldiers dead.