Google called off its flagship conference, the latest event cancellation as concern about the coronavirus grows among businesses.

The May event, called I/O, brings together thousands of people from around the world who partner with or build apps and websites for Google’s digital services. The company will refund participants and look for ways to hold sessions digitally instead, according to an email sent to participants that Bloomberg viewed. On Monday, Google made the same decision for its Cloud Next conference.

Conferences are particularly important in the technology industry, where companies must keep developers and users engaged on their platforms. The virus is undermining these efforts this year as travel plans are scrapped and companies increase protections for employees.

Facebook Inc. has already canceled its major developer conference, F8. Microsoft Corp. called off a smaller gathering, too. Tech industry conferences like the Game Developers Conference and Mobile World Congress were also scrapped. Apple Inc.’s major conference, WWDC, is typically held in June, but the company has yet to announce the event this year.

On Monday, Alphabet Inc.’s Google banned all business travel except in “critical” situations, according to a memo sent by Chief Financial Officer Ruth Porat that was seen by Bloomberg. The memo called for employees currently traveling abroad to return home as soon as they can.