A landslide at an illegal gold mine has killed at least 100 people in the Central African Republic on the border with Cameroon.

Search operations are still under way after the accident at the Zamboye mining site, about 50 kilometres from the Central African town of Baboua, on Tuesday afternoon.

Video images on social media showed a part of the ground at the huge open-pit mining site, where hundreds of artisanal miners work, break away and bury people in its path.

Several local sources said that around 100 people had died and many others were injured.

Judicial inquiry opened

"The ground completely collapsed and buried people," Cedric Mbango, a miner at the site, told AFP, describing the incident as "catastrophic."

The landslide is believed to have been caused by "the collapse of several underground tunnels in which miners were operating", the Baboua public prosecutor said in a statement, announcing a judicial inquiry had been opened.

"At this stage it's difficult for us to establish a formal toll," Baboua elected official Laurent Ngon Baba told AFP early on Wednesday.

At least four of the victims were Cameroonian, the Cameroon Tribune reported. Survivors were taken to hospital in Baboua, while the search continued on Wednesday.

Cameroon working with CAR in tragedy response

Gregoire Mvongo, governor of the eastern Cameroonian region, said on public CRTV radio that they were "working in close collaboration with our Central African colleagues to deal with the aftermath of this tragedy."

In June, a similar collapse killed several dozen at the Be-Mbari gold mining site, also on the Central African Republic-Cameroon border.

In mid-March, a landslide killed seven people at a mine in the village of Ngourroum, also in the west of the Central African Republic. Another 20 were killed in February in Gordi, in the northeast.