Kolkata, April 14 (IANS) At least 31 people were killed and over 50,000 houses destroyed when a massive storm swept through West Bengal's North Dinajpur district, snapping power and communication lines and uprooting trees, officials said Wednesday.

The storm with wind speed of 120 km per hour broke out at about 10.30 p.m. Tuesday and swept four blocks of the district, leaving thousands homeless and twisting trees with its ferocity. West Bengal Civil Defence Minister Srikumar Mukherjee described the situation as "very grave".

The four blocks, including dozens of villages in Karandighit, Itahar and Raiganj areas, were completely cut off, with mobile and telephone services and road communication disrupted.

Eighteen people died in the worst affected Karandighi block.

"The ferocity of the storm was such that it twisted trees. That is the reason I feel it was more than a mere norwester (a storm common in this part of the country," said the minister, who hails from the district.

"I have got reports of 31 deaths till now. Thousands are homeless. The situation is very grave.

"Not only mud houses, even pucca houses did not escape its wrath. There is no power supply. Land telephone and mobiles are not working. We are trying to maintain a semblance of contact with district officials through police wireless," the minister said over the phone.

Inspector General of Police (North Bengal) Kundan Lal Tamta told IANS that seven police barracks had collapsed but there no report so far of any casualty among the policemen.

"A large number of people seem to have been injured but we cannot confirm the figure now. Maybe, a lot of people are trapped under fallen trees and razed houses," Tamta said.

The government has cancelled leave of all officials and ordered relief and rescue operations on war footing.