Floods in Chad's northeast province of Tibesti have killed at least 54 people, the authorities said.

The flooding in the region following rainfall from last Friday to Wednesday had also swept away thousands of shops and vehicles, said Mahamat Tochi Chidi, governor of Tibesti province, late on Wednesday.

The torrential rains are a climate event that hits the region every five to 10 years, said Idriss Abdallah Hassan, head of the National Meteorological Agency.

Rainfall there normally struggles to reach 200 mm (nearly eight inches) a year, he added.

Most of the dead and missing are thought to be foreign informal gold miners working in the province, said Brahim Edji Mahamat, head of a local association.

Borkou-Ennedi-Tibesti, the zone spanning three northern regions of Chad that reach up to the border with Libya, is an immense, mountainous desert region.