Canadian plane makers De Havilland and Viking Air – both owned by Longview Aviation Capital – have pulled out of the Singapore Airshow, citing concerns over a coronavirus outbreak that has killed hundreds of people and sickened tens of thousands.

The move comes after the Singaporean government raised its health alert to the second-highest level Friday.

“In light of the increased alert level announced today by the Singapore Government and Ministry of Health due to incidents of Coronavirus in Singapore,” the companies said in a statement, “Longview Aviation Capital has elected to cancel the participation of its subsidiary companies, De Havilland Aircraft of Canada Limited and Viking Air Ltd. in the 2020 Singapore Airshow scheduled to be held from February 11th to 16th, 2020.”

“We advise event organisers to cancel or defer non-essential large-scale events,” Singapore’s Ministry of Health advised on its website. “For those who choose to proceed, they should take all necessary precautions.”

Those precautions include denying entry to people who are coughing or have a runny nose and reminding participants to stay home if they have travelled recently to mainland China.

Major airlines around the world have cancelled flights to China as the outbreak has spread. Air Canada cancelled flights from Vancouver, Toronto, and Montreal through the end of February.

Viking had planned to attend the Singapore Airshow as part of a world tour to drum up sales of a military version of its revived Twin Otter aircraft, a plane with a storied history in rugged locations.

The Guardian 400 is being marketed as a medium-range maritime patrol, search and rescue, and surveillance and security aircraft with lower costs than helicopters or traditional larger heavy lift aircraft.

De Havilland planned to show off a new Dash 8-400 from TrueNoord configured with 86 seats. It would have been the company’s first appearance at the Singapore Airshow, as the manufacturer works to revive sales under new owners.