A severe nor'wester swept six districts of West Bengal killing 13 people, damaging thousands of houses and snapping power and telephone lines.

The administration has warned of a fresh storm.

The official death toll is four -- three in lightning and one in a wall-collapse. But unofficial sources put it at 13.

The deaths were caused by lightning, wall collapse and falling of trees in Jalpaiguri, Murshidabad, Nadia, Bardhaman, North and South 24 Parganas districts.

A nor'wester accompanied by intermittent showers lashed the six districts on Wednesday and Thursday, officials said.

Chief Minister Buddhadev Bhattacharjee said reports indicated that the storm caused damage in Nadia and Bardhaman districts and asked the relief department to keep a watch on the situation. He also asked them to make provisions for relief materials.

Relief Minister H A Sairani said since Wednesday nor'westers and rain damaged about 3,000 houses in Nadia, 4,000 in North 24 Parganas and 120 houses in Jalpaiguri districts.

He said deaths were reported from Khandakosh in Bardhaman and one from Santipur in Nadia district.

He said a storm accompanied by thundershowers was likely to lash East Midnapore, West Midnapore, Howrah, Hooghly and North 24-Parganas with a wind speed of 70 to 80 kmph.