South Korea re-issued a travel alert Saturday for Toronto, Canada, for worry about the situation of the severe acute respiratory syndrome (SARS) in the North American country.

"The travel alert for Toronto has been reinstated as five probable SARS case were reported at a hospital in the city's northern outskirts on Thursday," according to a statement of the South Korean National Institute of Health (NIH).

The reinstatement follows a similar one by the US Centers for Disease Control and Prevention.

On March 16, the South Korean top state health agency issued a travel alert for the city, but lifted it on May 18.

According to the NIH, it will check the temperatures of South Korean people returning from Canada, have them fill out quarantine questionnaires and take other disease-preventing measures. The institute also advised South Korean travelers to Canada to pay close attention to personal hygiene.

Following the spread of SARS in Asia, the NIH has issued travel alerts for China, China's Hong Kong, Singapore, Mongolia and China's Taiwan.

Up to now, South Korea still retained only 3 probable SARS cases.