Saudi Arabia's King Salman has sanctioned the powerful Saudi Binladin Group over the collapse of a construction crane at Mecca's Grand Mosque which killed more than 100 people days before the hajj pilgrimage.

An investigative commission has concluded that the company “was in part responsible” for Friday’s tragedy, which killed at least 107 people and injured almost 400 during a severe thunderstorm accompanied by violent winds.

The company had not “respected the norms of safety” at the site, the official Saudi Press Agency said.

The firm’s executives have been forbidden from leaving the kingdom pending the completion of legal action against the company, SPA said.

During the same period, the company will also be excluded from new public projects.

The construction firm belongs to the family of the late al-Qaeda leader Osama bin Laden.

It had been working for four years on a 400,000-square-metre enlargement of the Grand Mosque to accommodate increasing numbers of pilgrims.

That is the equivalent of more than 50 football pitches, and will allow the complex – Islam’s holiest site – to accommodate roughly two million people at once.

After visiting the scene of the tragedy, Salman vowed to reveal what happened.

It was the worst accident in a decade surrounding the hajj,  which is expected to draw about two million faithful from around the world this year.

Hundreds of thousands had already converged on the Grand Mosque when the red and white crane, one of several overlooking the site, crashed into a courtyard.

Saudis, Iranians, Nigerians, Malaysians, Indonesians and Indians were among the dead.

By Ian Timberlake