Hong Kong and parts of southeastern China shut down Tuesday as authorities urged residents to stay home and suspended most passenger flights through Thursday ahead of Super Typhoon Ragasa, the world’s strongest tropical cyclone this year.

People piled into supermarkets, leaving little on the shelves, as panic buying set in and residents stocked up on necessities for fear that shops could be closed for two days.

Windows in homes and businesses across the city were taped up, with residents hoping it could help reduce the impact of any shattered glass.

Ragasa, packing hurricane-force winds of up to 220 kph (137 mph), is posing a "severe threat to the coast of Guangdong," the Hong Kong Observatory said, referring to the Chinese province that neighbors the financial hub.

It will maintain super typhoon intensity as it edges closer to the coast of Guangdong, and as it impacts Hong Kong, mainland China and Taiwan, after sweeping through the northern Philippines on Monday. It is expected to make landfall along Guangdong's coast from midday to late Wednesday.