PARIS (AP) — A French patient infected with a deadly new respiratory virus related to SARS died Tuesday of the disease, which has killed half the people known to be infected and alarmed global health officials.

The novel coronavirus is related to SARS, which killed some 800 people in a global epidemic in 2003. Dr. Margaret Chan, head of the World Health Organization, singled out the illness in a speech on Monday in Geneva.

"We understand too little about this virus when viewed against the magnitude of its potential threat," Chan said at the annual WHO meeting. "We do not know where the virus hides in nature. We do not know how people are getting infected. Until we answer these questions, we are empty-handed when it comes to prevention. These are alarm bells. And we must respond."

WHO said in an update earlier this month that 20 of the 40 confirmed cases of the disease have ended in death. Most of those infected since the virus was identified last year had traveled to Qatar, Saudi Arabia, Jordan or Pakistan. There also have been cases in Britain and Germany.

The ministry said the Frenchman, whose illness was identified May 8 after he returned from a visit to the United Arab Emirates, died Tuesday. His hospital roommate also tested positive for the illness.

Meanwhile, the Saudi Health Ministry reported five new cases of the virus. All the patients were in their 70s or older.