Saudi Arabia's civil defense authority said on Friday that at least 107 people had died as a result of the accident, with at least another 238 injured.

Pictures on social media showed debris from the crane, which appeared to have crashed through the ceiling.

Ahmed bin Mohammed al-Mansouri, the spokesman for the presidency of the Mecca and Medina mosque affairs, said in a statement carried by the official Saudi Press Agency that the accident happened late Friday afternoon during a severe storm blowing strong winds and heavy rain.

Authorities have not provided details on the victims' nationalities, but it is likely that the tragedy will touch several countries. Already the Iranian News Agency has reported that 15 Iranian nationals were among the injured.

The region's governor, Prince Khaled al-Faisal, has ordered an investigation into the incident.

Preparations were underway for the annual Muslim Hajj pilgrimage later this month. Saudi authorities go to extensive lengths to get ready for the millions of Muslims who visit Mecca for the event.

Saudi Arabia last year reduced the numbers of people allowed to perform Hajj, amid safety concerns because of construction work to enlarge the Grand Mosque.

The area of the mosque is to be increased by 400,000 square meters (4.3 million square feet), which would allow the mosque to accommodate up to 2.2 million people at one time.

The pilgrimage has experienced tragedy in the past, mainly from stampedes as pilgrims hurry to complete rituals before returning home. Hundreds died in a stampede in 2006.

rc/mkg (AP, AFP, Reuters)