July 18 (UPI) — At least four people were killed and 18 injured, including children and seniors, after a high-speed multi-vehicle collision in San Antonio on Interstate 35, the city’s Police Department said.

The Thursday afternoon incident occurred when a stolen Chevy Camaro being driven at high speed reportedly crashed into a small passenger bus towing a trailer.

Police said they were looking for four suspects, one of whom was armed, who left the scene and asked people to avoid the Leon Creek section of southbound I-35.

“We had a stolen white Camaro south on 35 speeding wrecked into a small transport bus carrying a trailer. As a result of that crash, two individuals are dead. 18 have been transported to hospitals,” said San Antonio Police Chief Bill McManus.

“There are four individuals who fled from the vehicle. One was armed with an AK rifle,” he added.

Bus operator, Fort Worth-based Transport Guerra, asked relatives of passengers who were on the Mexico-bound service to call their office.

The bus was scheduled to stop in Eagle Pass on the border, before crossing into Mexico with stops in the Carbonifera coal mining region and “5 manantiales.”