QUETTA, Pakistan (AP) — A minibus packed passengers collided with a pickup truck carrying gasoline in southwestern Pakistan on Friday, killing at least 13 people.

According to police, the pickup truck was carrying fuel smuggled from neighboring Iran in plastic containers. The minibus caught fire in the collision, which took place in Kan Mehtarzai, a town about 75 kilometers (50 miles) north of Quetta, the capital of impoverished Baluchistan province.

It was unclear what caused the accident; police were investigating.

Road accidents are common in Pakistan where traffic laws are poorly enforced.

The country’s southwestern Baluchistan province lies on a key smuggling route. It borders Iran, from where smuggling contraband fuel is common due to significant difference in fuel prices in the two countries. In January, 27 people were killed in Baluchistan in a collision between a bus and an oil tanker.