A man tested positive for COVID-19 Monday as he was preparing to carry out a required military refresher course, the Swiss armed forces said in a statement.

In Switzerland, which has detected more than 35 cases since the virus first emerged in the country a week ago, the army is organised as a militia, with conscripts carrying out a short initial training and then called back in for several weeks of training each year.

During the health screening required before the course, the infected man revealed that he had recently returned from Milan in northern Italy, the statement said.

Italy is the European country hardest hit by the outbreak, it said, adding: "He is in stable condition."

The three people in his room were immediately quarantined, as were other conscripts who had come in contact with him.

The army said it had also decided to limit the movement of on-duty troops to ensure they will be ready to respond quickly if needed.

Soldiers can still leave their barracks but have been asked not to leave the military installations unless absolutely necessary, army spokesman Daniel Reist told AFP.

In a bid to rein in the spread, Switzerland last Friday suspended all events with more than 1,000 participants until March 15, forcing the cancellation of several large events including the Geneva International Motor Show.

The UN's European Geneva headquarters has also closed its doors to visitors and has curbed some activities linked to the Human Rights Council.