At least 45 people were killed and one seriously injured after a bus headed to an Easter conference plunged off a cliff in South Africa's Limpopo province on Thursday, CNN reported.

All the deceased were pilgrims travelling from Gaborone, the capital city of neighbouring country Botswana, to a church for an Easter conference, the South Africa Broadcasting Corporation (SABC) said.

SABC said that the sole survivor is an eight-year-old girl who has been airlifted to the hospital.

CNN reported that the crash happened in the Mamatlakala mountain pass between Mokopane and Marken. The bus reportedly caught fire after falling.

The cause of the crash is under investigation.

In a statement, the province's transport department said that "according to reports, the driver lost control and the bus fell onto a rocky surface, some 50 meters under the bridge and caught fire."

Efforts are ongoing to recover the bodies of the passengers who were killed, according to the statement.

"Some bodies burned beyond recognition," the local department said. Others are "trapped inside the debris and others [are] scattered on the scene," it added.

South African Transport Minister Sindisiwe Chikunga said the government would repatriate the bodies to Botswana, the broadcaster said, CNN reported.

"I am sending my heartfelt condolences to the families affected by the tragic bus crash near Mamatlakala. Our thoughts and prayers are with you during this difficult time. We continue to urge responsible driving at all times with heightened alertness as more people are on our roads this Easter weekend," Chikunga said in a statement.(ANI)