Several people were reportedly killed and injured inside the Grand Mosque in Makkak when a construction collapsed due to bad weather, medical sources said.

Duabi: At least 107 people were killed and 238 others injured after a crane fell in Makkah’s Grand Mosque on Friday, according to Saudi Arabia’s Civil Defence authority, reports Reuters.

Ahmed Bin Mohammad Al Mansoori, spokesman for the two Holy Mosques, was quoted by the official Saudi Press Agency as saying part of a crane collapsed at 5:10 pm (1410 GMT) "as a result of strong winds and heavy rains."

Abdel Aziz Naqoor, who said he works at the mosque, told AFP he saw the crane fall after being hit by the storm.

"If it weren't for Al-Tawaf bridge the injuries and deaths would have been worse," he said, referring to a covered walkway that surrounds the Holy Kaaba, which broke the crane's fall.

The governor of Makkah region, Prince Khaled Al Faisal, has ordered an investigation into the incident, which came just weeks before the Muslim annual Haj pilgrimage.

No details were immediately available on the nationalities of the victims. Iran's official Irna news agency, quoting the head of the Haj Organisation, said that 15 Iranian pilgrims were among those injured.

The civil defence authority said on Twitter that emergency teams were sent to the scene after a "crane fell at the Grand Mosque." That came about an hour after it tweeted that Makkah was "witnessing medium to heavy rains".

Kuwait News Agency Kuna reported that the “giant" crane’s fall was caused by heavy rain and strong winds in Makkah on Friday night.

Several cranes surround the mosque to support an ongoing expansion and other construction work that has transformed the area around the sanctuary.

Health authorities declared a red alert and the head of the Red Crescent in Makkah said that 39 ambulances were promptly dispatched to the mosque to treat and transport the injured.

The Grand Mosque is usually at its most crowded on Fridays, the Muslim weekly day of prayer. It houses the Kaaba - the massive cube-shaped structure towards which Muslims worldwide pray.

Pictures circulating on social media showed pilgrims in bloodied robes and masses of debris from a part of the crane that seemed to have crashed through a ceiling.

Meanwhile, online activists created a hashtag on Twitter urging Makkah residents to donate blood at hospitals in the area.

Saudi authorities go to great lengths to be prepared for the millions of Muslim who converge on Makkah to preform the sacred pilgrimage.

Last year, the kingdom reduced the numbers permitted to perform Haj for safety reasons because of construction work to enlarge the Grand Mosque.

The Haj has largely been incident-free during the past few years, with the kingdom investing billions of dollars in transport and other infrastructure to facilitate the movement of the huge numbers of people who take part.

Khaled Al Habshi, head of the Red Crescent in Makkah, said 39 ambulances had been mobilised to receive the injured.

A massive project is currently underway to increase the area of the mosque by 400,000 square metres, allowing it to accommodate up to 2.2 million people at once.

Around two million people are expected to be in Makkah within 10 days to perform pilgrimage, the last of the five pillars of Islam. Thousands of would-be pilgrims have already reached the city.

- with inputs from Habib Toumi, Bahrain Bureau Chief, and agencies