At least 21 people have been killed and another four injured in a head-on collision between a minibus and a lorry in southern Brazil, local officials say.

The crash happened at around 04:30 local time (07:30 GMT) on the BR-373 highway in the southern state of Paraná.

Local media reported that the minibus belonged to the health authorities of the nearby city of Imbituva and was transporting patients and their relatives to health appointments in Ponta Grossa, some 60km (36 miles) away.

Authorities have opened an investigation to determine what may have caused the two vehicles to crash into each other.

Deadly road traffic accidents are not uncommon in Brazil.

According to a study published by the World Bank, more than 34,000 people died in such accidents in 2023, most of them were motorcyclists.

Research suggests excessive speed, inebriated drivers and the use of mobile phones while driving is often the cause.

In February, 15 people died on board a bus carrying pilgrims to a festival in the north-eastern state of Ceará.