A head-on collision between a bus carrying medical patients and a truck killed at least 23 people early on Wednesday in southern Brazil, highway police said.

The crash occurred at 3.30 am local time when the truck veered into the other vehicle's lane in the municipality of Ipiranga in Parana state, police said.

"At least 23 deaths have been confirmed. Most of the victims were on the bus," authorities said in a press release. The truck driver was among those killed.

Images in the local press showed the bus smashed to pieces next to a truck at the roadside.

Initially, the company that manages the highway said the accident took place in Imbituva, where the bus began its journey.

The collision occurred on a highway that connects the southern part of the country with Sao Paulo, Brazil's wealthiest state.

Hours later, the highway remained closed, causing a kilometres-long backup of vehicles.

The bus belonged to the Imbituva health department and was transporting patients to medical centres in the city of Curitiba.

Authorities have not provided any information about the truck's occupants. (AFP)



Edited by Cecil Wong