At least 13 people were killed in a road accident after four fuel-smuggling trucks crashed into each other in southeastern Iran, state television reported Sunday. The report said the accident happened when the four trucks, which were carrying a total of 17 people and thousands of litters of fuel, were traveling on the road with their headlights turned off to avoid detection by police, The Associated Press reported. The trucks crashed and caught fire on the road, which links Zahedan to Mirjaveh near the Pakistan border about 1,500 kilometers (932 miles) southeast of Tehran, the report said. The four other people inside the trucks were taken to a local hospital with severe injuries.