A convoy of six fuel tanker trucks exploded on Peru’s Central Highway, which connects several central Andean cities causing an undetermined number of deaths and injuries, National Police Chief of Highway Colonel Erlyn Silva said.

In an interview with the local media on Saturday, Silva explained that the accident was caused by rocks falling from a hill that hit one of six trucks carrying gasoline, causing a chain explosion on the interprovincial highway 85 km east of capital Lima, reports Xinhua news agency.

“A rock hit the first vehicle and as a result of that impact, it broke the tank, and that caused a spill to occur for many meters along the road, and that spill caught fire immediately at the time of the explosion,” Silva explained.

About 10 firefighting units were working in the area to put out the fire and help the injured.

The explosion also affected cars and other vehicles on the highway.

The Ministry of Transport and Communications reported on Twitter that traffic is restricted in the area and drivers are recommended to take precautions.