At least 24 people have been killed when two passenger trains derailed separately in central India after heavy monsoon rains submerged railway tracks.

Ten coaches from the trains toppled into the swollen Mochak river last night while crossing a small bridge in Madhya Pradesh state.

The accidents - involving one train en route from Mumbai to the temple city of Varanasi, and another headed in the opposite direction - occurred within minutes of each other.

As many as 300 people have been rescued at the accident site, about 160km south of the state capital Bhopal.