At least 107 people were killed when a construction crane collapsed onto Mecca's Grand Mosque during a storm Friday.
Saudi Civil Defence reported at least 238 people injured, and that figure was expected to continue rising as it conducted a rescue operation at the world's largest mosque.
The Masjid al-Haram surrounds the Kaaba, Islam's holiest site, where Muslim pilgrims from around the world gather to worship.
Authorities said a heavy rainstorm with high winds caused the crane to topple.
Photographs on Saudi websites showed debris from the fallen crane, which crashed through the ceiling of the mosque, as well as people carrying bloodied bodies.
The Grand Mosque is normally crowded on Fridays.
The broadcaster said that a huge construction project was underway to expand the Haj pilgrimage sites area by 400,000 square metres and to prevent accidents like stampedes.
In 2006, a stampede during the Haj pilgrimage season killed nearly 350 people.
"All hospitals in the city has been put on high state of alert and were enhanced by blood units to be able to cope with the high number of wounded," Abdel al-Wahab Shalabi, health department spokesman in Mecca was quoted as saying by the Saudi Press Agency.
There were no immediate reports on the nationalities of the dead and injured victims.
The accident occurred as the Saudi city was preparing to receive more than 1 million Muslims from all over the world this month for the annual Haj, which begins September 21.
Muslims are expected to perform the Mecca pilgrimage at least once during their lifetimes.

The crane collapsed due to a storm with heavy rain and high winds. (AFP/File)