ANTANANARIVO, June 3 (Xinhua) -- Eleven artisanal gold miners were killed early Tuesday in a landslide at a gold mining site in Vatomandry, eastern Madagascar, authorities said Wednesday.

Preliminary investigations revealed that the victims were working at night when the landslide occurred, which made rescue efforts harder, Gabin Razafindrakoto, commander of Vatomandry gendarmerie brigade, told Xinhua.

The mayor of the city has ordered the immediate closure of the site to prevent any further mining activities and reduce the risk of additional incidents, he said.

Authorities are trying to determine the exact circumstances of the landslide. ■