PORTLAND – Three students from Maine colleges and universities are studying in China, but all have decided to stay there despite the threat of the SARS virus.

The students – from Bowdoin College, Colby College and the University of Southern Maine – were given the option of returning to the United States, but decided to stay. School officials said the students are in Beijing, and another Bowdoin student is studying in Vietnam, which borders China.

With students overseas, and school trips and study-abroad programs planned in the months ahead, school officials are keeping a wary eye on the spread of SARS, or severe acute respiratory syndrome. The virus has infected 4,400 people and killed more than 260 worldwide; roughly half the cases have been in China.

The threat was enough for Bates College to cancel a spring trip to Beijing for 10 students and two faculty members. A decision is due soon on a fall trip to Nanjing for 25 students and two faculty members.

“It’s the uncertainty, the risk of the disease,” said Stephen Sawyer, associate dean of students and director of off-campus study programs.

Global health officials are warning travelers to avoid Beijing and Toronto, where they could contract the virus and carry it to new locations. Canadian officials are insisting their nation’s largest city still is “a safe place,” despite 19 deaths there as of Friday.

In Beijing, all public schools are closed for two weeks, affecting 1.7 million children.