Hundreds of Canadian and international military performers in Halifax are being tested for the swine flu after at least one performer became sick with the virus.

The military says there are three performers ill with the swine flu at the Royal Nova Scotia International Tattoo, and they are all civilians. One is a member of a dance troupe from the province.

Cmdr. David Wilcox, a physician with the Department of National Defence, said eight military performers have flu-like symptoms.

It's not known if they're members of the Canadian Armed Forces or from outside the country. None of them will take part in the final show Wednesday night.

The floor of the Metro Centre was turned into a makeshift clinic Wednesday as testing began on 400 members of the Canadian military and 250 from international forces.

Performers filled out a questionnaire and had their temperature taken. Swabs were taken, if warranted.

Wilcox said the goal is to prevent the spread of the swine flu or any other virus.

"Our approach is to try to stop influenza at the gate, so what we want to do is screen them before they travel in an attempt to prevent the influenza from entering the camps," he said.

The 1,000 civilian performers are being urged to stay home and avoid crowds if they're not feeling well. Unlike their military counterparts, they weren't screened for the flu.

Dr. Graeme Bethune, a Nova Scotia physician and medical adviser to the Tattoo, said there is no need to do that because it's the military performers who share close quarters.

The show is expected to go on Wednesday night as planned. None of the groups has cancelled.

The doctors said there is little risk to spectators.