CHAGHI - At least four people were killed and 11 others injured in a collision between two over speeding vehicles here on Thursday. According to details, a Quetta-bound bus coming from Tuftan collided head-on with a car on RCD Highway in Padad area of district Chaghi. Four people includingcar driver were killed in the accident while 11 others were injured. Sources said that the victims were illegal immigrants.