At least 107 people have died after a crane toppled over and crashed into the Grand Mosque in the Saudi city of Mecca.
Another 238 people were injured when the crane, which was being used in construction work, collapsed during a violent rainstorm.
The Grand Mosque is the largest in the world and surrounds Islam’s holiest place, the Kaaba.
Pictures circulating on social media showed pilgrims in bloodied robes and debris strewn over the floor.
“All those who were wounded and the dead have been taken to hospital,” said General Suleiman al Amr, director general of the Civil Defence Authority. “There are no casualties left at the location.”
Images aired on Saudi state television showed the crane’s boom had smashed through what appeared to be the roof of the mosque.
Authorities have not provided details of the victims’ nationalities.
Foreign Secretary Philip Hammond said he was “shocked and saddened to hear of the accident”, adding: “My thoughts are with the families of those affected.”
Millions are expected to descend on Mecca later this month for the annual hajj pilgrimage.
The pilgrimage – which all able-bodied Muslims have a duty to do at least once in their lifetime – is one of the largest religious gatherings in the world and has been prone to disasters,
Hundreds of pilgrims died in a stampede in 2006.
Saudi authorities have lavished vast sums to expand the main hajj sites and improve Mecca’s transportation system in an effort to prevent further problems.
The crane that fell onto the mosque was one of several being used in the expansion and other construction work that has transformed the area around the sanctuary.