India, Oct. 5 -- West Bengal chief minister Mamata Banerjee expressed "deep worry" about the flooding of several areas in both North Bengal and South Bengal due to sudden heavy rains, with at least 18 people dead in the state and 40 more in neighbouring Nepal.

The toll is expected to rise as the rescue operations continue..

Banerjee assured that all necessary assistance would be sent to the affected families immediately.

CM Banerjee also described the widespread devastation that struck North Bengal after torrential rains exceeded 300 mm in just 12 hours, causing disasters.

"Yesterday (October 4-5) night there was sudden rainfall exceeding 300 mm in 12 hours in North Bengal, and there was simultaneously excessive flow of water into San...