Crane collapse kills 107 at Mecca's Grand Mosque ahead of Hajj

At least 107 people were killed on Friday after a crane crashed into Mecca's Grand Mosque on its busiest day of the week, according to Saudi Arabia's civil defence authority.

Another 238 people were reportedly injured when the crane fell through an area in the mosque's eastern arena, during heavy rains and strong winds.

Hundreds of people could be heard screaming and running for cover in the videos showing the incident.

Photos circulating on social media showed bloodied bodies strewn across a courtyard where the crane crashed.

The collapse comes as millions are expected to arrive in Mecca for the annual Hajj pilgrimage by 21 September.

A team of 15 Saudi civil defense officials, a search and rescue team and the Red Crescent is reportedly currently at the mosque to assist the wounded.

A massive project is currently underway at the mosque to increase its size by 400,000 square metres, allowing it to accommodate up to 2.2 million people at once. As a result, it is surrounded by several cranes at the moment.

The Hajj has largely been incident-free during the past few years, with Saudi Arabia investing billions of dollars in transport and other infrastructure to facilitate the movement of the huge numbers of people who make the pilgrimmage. 

In the past, there have been major stampedes, mostly in Mina, about four miles outside of Mecca, where Hajj pilgrims go to carry out a ritual in which stones are thrown at a wall, representing the devil, to purge themselves of sin.

In 2006, at least 345 pilgrims were killed and 1,000 injured in Mina when they were reportedly tripped up by luggage and then crushed by the crowd behind them.