Four miners were rescued after being trapped for over 31 hours in a flooded mine pit in northwest China's Heilongjiang Province, local authorities said on Wednesday.

The flood occurred around 4:30 a.m. Tuesday in the city of Shuangyashan. Twenty-eight miners were working in the pit when the flood occurred; 22 of them managed to escape, according to a spokesman from the city's work safety supervisory group.

The four rescued miners have been sent to a local hospital and their condition has been described as stable, according to the spokesman.

The remaining two miners perished in the flood; both of their bodies have been recovered, the spokesman said.

The cause of the flood is under investigation.