LA OROYA, Peru (AP) — Four people were killed and more than 30 others were injured after a passenger bus and a cargo train collided Sunday in central Peru, the country's national police said.

Authorities said the crash happened after 4 a.m. in the district of La Oroya, about 110 miles (177 kilometers) east of the capital, Lima. The Ministry of Transportation and Communications in a statement said the cause is under investigation. The train and bus, both privately operated, had all the required permits, it added.

The ministry said all of the injured were taken to a nearby hospital. The agency did not immediately release the names of the deceased.

The bus had set out from Lima and was headed to the city of Huancayo. Images released by police show the overturned bus on the Central Highway.