The World Health Organization says a Qatari man is critically ill in a London hospital after displaying symptoms similar to the deadly SARS virus.

In a statement Monday, WHO representatives said the 49-year-old unnamed patient was suffering from acute respiratory infection and kidney failure.

A 60-year-old Saudi national died from a similar virus earlier this year.

WHO officials say that the current patient first showed symptoms on September 3 after a trip to Saudi Arabia. Four days later, he was admitted to an intensive care unit in Doha. On September 11, he was transferred to Britain by air ambulance where he underwent laboratory testing.

At this point, the WHO is not recommending any travel restrictions. The source of the infection remains unknown.

During an earlier SARS outbreak in Asia, travel restrictions were imposed.