Following the discovery of a rare and deadly virus belonging to the same family as SARS virus in a 49-year-old Qatari man, the World Health Organisation (WHO) on Wednesday, urged health workers to immediately report acute respiratory infection cases.

The health advisory comes ahead of the Haj pilgrimage that begins next month. More than 2 million Muslim pilgrims are expected to flock the Kingdom of Saudi Arabia.

The UN health body had put out a global alert on August 23 after identifying a new virus in the Qatari man who had travelled to Saudi Arabia, where another man with an almost identical virus had died.

Though no fresh cases of the new virus has been reported so far, the WHO is working closely with Saudi authorities on health measures for the Haj.

WHO`s clinical guidance to its 194 member states said that health workers should be alert to anyone with acute respiratory syndrome and requiring hospitalization who had been in the area where the virus was found or in contact with a suspected or confirmed case within the previous 10 days.

WHO said it was identifying a network of laboratories that could provide countries with expertise on coronaviruses.

"Though it is a very different virus from SARS, given the severity of the two confirmed cases so far, WHO is engaged in further characterizing the novel coronavirus," it said.

The new virus shares some of the symptoms of SARS, another coronavirus, which appeared in China in 2002, infecting over 8,000 people and killing nearly 800 before being controlled.

Saudi Arabia has assured that it has taken precautions to prevent disease spreading next month.

The WHO has so far not recommended any travel restrictions.