New Delhi, May 21 (IANS): A day of killing 12 people after barrelling in from the Bay of Bengal with wind speeds up to 185 kmph, severe cyclonic storm Amphan on Thursday weakened and lay centered over Bangladesh about 270 north-northeastwards of Kolkata with a wind speed of 27 kmph.

The super cyclonic storm Amphan (pronounced as UM-PUN) moved "north-northeastwards with a speed of 27 kmph during the past six hours, further weakened into a cyclonic storm and lay centered at 5.30 a.m. on Thursday over Bangladesh near latitude 24.7°N and Longitude 89.5°E about 270 km north-northeast of Kolkata, 150 km south of Dhubri and 110 km south-southeast of Rangpur (Bangladesh)", the India Meteorological Department (IMD) said.

"It is very likely to continue to move north-northeastwards and weaken further into a deep depression during the next three hours and into a depression during subsequent six hours," the IMD said.

It said that the Cyclone is now centred over Bangladesh and it will have no adverse impact over West Bengal and Odisha -- a good sign as it cut a swathe through northern Odisha before bearing down on West Bengal where it claimed 10-12 lives, flattened houses and cast aside trees and electricity poles like matchsticks in six-and-a-half hours of monstrous fury that left Kolkata and most of south Bengal pulverised.

While Odisha was spared the worst of Amphan, the Suderbans region and six south Bengal districts felt the full impact of winds gusting at 155-165 kmph along with torrential rain after the cyclone made landfall near Sagar Island around 2.30 p.m. on Wednesday and entered Kolkata, about a 100 km north, around 5 p.m.

Amphan, a Thai name that means sky, is the most severe storm in the Bay of Bengal since the Odisha super cyclone of 1999.