A tornado swept through a trading town Thursday, killing at least 13 people and injuring about 100, a news agency said. It was the latest in a series of natural calamities torturing Bangladesh.

The twister, the third in as many days, destroyed mud huts and extensively damaged homes on Sirajgang, 65 miles northwest of Dhaka, according to United News of Bangladesh. No further details were given.The tornadoes followed last week's catastrophic cyclone on the southeastern coast that killed more than 125,000 people and left millions homeless.

During Wednesday's tornado, eight people were killed and about 100 injured in Ghorasal, a farming village one mile southeast of the devastation left by a twister 24 hours earlier. The tornado on Tuesday claimed 45 lives.

Houses in eight villages were flattened and trees and electricity pylons were toppled Wednesday about 10 miles north of the capital, the daily Ittefaq said.

Meanwhile, a heavy downpour and 60 mph winds in Dhaka disrupted relief flights for survivors of the killer cyclone on April 30.

"This was the strongest wind speed of this year" in the Bangladesh capital, a weather bureau official said. Airport officials said all flights were grounded during the afternoon, and some Dhaka streets were flooded under knee-high water.

Bangladesh appealed Thursday for more helicopters and transportation to deliver food, clothing and rudimentary shelter to millions of survivors from the cyclone - the Indian Ocean's version of a typhoon.

The weather bureau, in its monthly forecast printed Thursday, warned that a depression over the Bay of Bengal could produce another cyclone before the end of the month. It did not predict whether the storm would strike land.