At least 21 people were killed and more than 40 injured when two passenger buses collided head on near Thatta, about 90 km north of Karachi, news reports said on Tuesday. Those killed in Monday’s accident included the drivers of both buses, police said. According to the reports, the crash occurred after one of the drivers speeded up to pass another vehicle. Both buses were packed with passengers, with some even riding on the roofs of the two vehicles, the reports said. Nineteen people were dead at the scene of the accident and two others died in hospital. Five of those injured were in critical condition, doctors said. Bureau Report