A powerful cyclone that battered the coast of Bangladesh Saturday left at least 21 people dead and forced the relocation of over 500,000 people from low-lying areas.

“We've shifted most of the people who are vulnerable,” Bangladesh’s Disaster Management and Relief Minister Mofazzal Hossain Chowdhury Maya, reportedly said. “All-out preparations are in place to tackle the damage.”

The cyclone, named “Roanu,” made landfall at noon local time Saturday (2 a.m. EDT), packing winds of up to 56 miles per hour and triggering floods and landslides. The nation’s impoverished southern and southeastern regions, including Chittagong, Barisal and Bhola were the worst affected, according to media reports.

“The authorities announced that the cyclone would hit around noon Saturday. But gusty winds and the surge in the sea began almost 10 hours ago, beginning to wreak havoc in our island just after the midnight. Many got no time to move themselves to safety or secure their houses, shops,” Rashid Sadi, a fish trader in Tajumuddin, Bhola district, told Voice of America.

All flights to and from Chittagong airport have been suspended and authorities have also restricted movement of ships and ferries in the region.

“Using mobile microphones in all coastal districts, our officials sent across the warning about the cyclone. We mobilized forces and evacuated the people from the vulnerable coastal areas. We also restricted the movements of boats, barges and fishing trawlers since Friday,” Mesbah Uddin, Chittagong district’s chief administrator, reportedly said.

The storm system has since weakened and moved eastward to India’s Mizoram state.

The delta nation of Bangladesh is no stranger to fierce tropical cyclones, which hit the country every year. One of the deadliest cyclones the region has witnessed was “Bhola,” which killed nearly 500,000 people in 1970.

“We have experiences from Cyclone Komen [which struck Bangladesh last year] and successfully used those to face Roanu,” senior disaster management official Shah Kamal told the Daily Star.