Delta, which does not fly to Hong Kong, said it would suspend service through April 30. Delta said in a statement that its last flight to mainland China from the United States would depart on Monday, and that its last flight to the United States from mainland China would leave on Wednesday.

Delta was the first American airline to completely suspend service to China because of the virus. United Airlines had already reduced its service to the country this week.

Share prices in all three airlines had fallen by midday.

Airlines outside the United States are also clamping down on travel. In Rwanda and Kenya, RwandAir and Kenya Airways said they would cancel all flights to and from Guangzhou, the southern Chinese metropolis, until further notice. There have been no confirmed cases in Africa.

Poland’s national airline, LOT Polish Airlines, has suspended flights to China until Feb. 9, a deputy prime minister said on Twitter. More than a dozen people suspected of having the coronavirus are hospitalized in Poland, and over 500 people are being monitored by health services.

Iran has suspended all flights to China because of the coronavirus outbreak, according to Reuters. Iran’s semiofficial Tasnim news agency reported on Friday that all flights from China to the Islamic Republic have also been banned.

Several Canadian companies have suspended employee travel to China after Air Canada’s decision on Wednesday to suspend service to Shanghai and Beijing. The Montreal-based carrier normally operates 33 flights a week to and from the two Chinese cities.

Americans evacuated from Wuhan are quarantined.