HONG KONG, September 16, 2018 (News Wires) -- Hong Kong residents huddled indoors Sunday as strong wind sent debris flying ahead of the arrival of Typhoon Mangkhut, once the world's strongest storm this year before it weakened after slamming into the Philippines. Almost 900 Hong Kong flights had been cancelled ahead of dangerous typhoon. Airlines and passengers over parts of Asia have been grounded as Typhoon Mangkhut arrives in Hong Kong and China's Guangdong province. According to the Hong Kong Airport Authority, 889 flights have been canceled on Sunday because of the storm. The city's Airport Express train and bus service have also been suspended. Cathay Pacific Airways Ltd. said in a statement that it was expecting "severe disruptions" and won't resume operations until 4 am Monday. The airline has canceled more than 400 flights. Cathay Dragon and Hong Kong Airlines also grounded their fleets on Sunday. Hong Kong International Airport said ferry services between the airport and all of the Pearl River Delta ports had been suspended until further notice. AirAsia Group Bhd said service disruption was expected to continue through Monday. It canceled all flights to and from Hong Kong, Macau, Guangzhou, Shenzhen and Shantou, and axed 29 flights on Saturday. Philippine Airlines Inc. is scrapping 10 international flights on Sunday. Hong Kong issued its highest storm warning as the typhoon's top winds declined to about 167 kilometers per hour (103 mph), from 195 kph earlier, according to the U.S. Navy and Air Force's Joint Typhoon Warning Center in Hawaii. The Hong Kong Observatory (HKO) raised the storm signal to T10 — the highest level possible — Sunday morning local time, as the storm continues to carve a destructive path from the Philippines towards mainland China. Fierce winds have already torn off roofs and caused partial building collapses in Hong Kong, as authorities warned of the threat of storm surges and flooding from torrential rain. The city is almost entirely shut down.