Four people were killed and five others badly injured when a truck hit a bus Friday morning in central Vietnam, an official said, according to DPA. The 24-seat bus, carrying around 20 passengers, was on the way to Tuy Hoa City in Phu Yen province, 1,156 kilometers south of Hanoi, at 6:30 am when it was hit by a truck going in the opposite direction. "Four passengers were killed and five others badly injured," said Ngo Van Uong, director of the provincial Traffic Police Department. Police detained the driver of the truck Pham Manh Dung for questioning as they investigate the cause of the accident, he added. "The truck hit to the left side of the bus, killing and injuring people sitting near the windows of the left rows, but the bus didn't turn upside down," Uong said. Road crashes have killed 5,663 people in Vietnam in the first six months of this year, compared with 5,360 people in the same period last year, according to government statistics.