Kolkata, Jun 6 (IANS): With a heat wave prevailing across southern West Bengal, the death toll rose to 42, with 12 more people succumbing Wednesday in Kolkata and the districts, police said.

"Four people each in Burdwan's Asansol, Jhargram in West Midnapore and two each in Hooghly and Kolkata died Wednesday due to the extreme heat. Several people have been hospitalised across the state," a police officer said.

Chief Minister Mamata Banerjee has expressed concern over the heat wave toll and has instructed the district administrations to take precautionary steps.

"The chief minister has expressed deep concern over the rising number of deaths due to the heat and has asked the health department to issue necessary orders to the district administrations to take necessary steps," Minister of State for Health Chandrima Bhattacharya said.

Additional beds, generators and fans are being provided to the government-run hospitals in West Midnapore, Burdwan, Hooghly, Howrah and Birbhum. ORS packets, drinking water tanks and shelters along roads are being put up in the districts, added Bhattacharya.

Government hospital staff have been asked not to take any leave.

Thirty people reportedly died Tuesday in the heat wave.