At least 42 people have been killed in a bus crash on a steep mountain road in South Africa, authorities have said.

Seven children were among the victims, while 49 other people were injured.

The crash happened near the town of Louis Trichardt, in the northern province of Limpopo, nearly 250 miles north of the capital, Pretoria.

The bus was heading to Zimbabwe and was on a road, known as the N1, when it veered down an embankment at around 6pm on Sunday.

The cause of the crash is not yet known.

The victims included 18 women and 17 men, while six people were critically injured, the transport ministry said.

One seriously injured child was airlifted to a hospital, the ministry added.

Another 31 people had serious injuries and had been taken to several hospitals.

The bus was carrying Zimbabwean and Malawian nationals, who were on their way to their home countries, the ministry said.

The vehicle was said to be lying upside down on an embankment, with rescuers working beneath it as they searched for survivors.

South African president Cyril Ramaphosa offered “his deep condolences to the nations of Zimbabwe and Malawi who have lost compatriots”.

“This incident is a tragedy for South Africa and our sister states of Zimbabwe and Malawi alike,” he added.

“This sadness is compounded by the fact that this incident has taken place during our annual transport month, where we place a special focus on the importance of safety on our roads.”

Last year, 45 people were killed in a bus crash in the same Limpopo province when the vehicle veered off a bridge and into a ravine.

An eight-year-old girl was the only survivor.

- Agencies