President Muhammadu Buhari and Senate President Bukola Saraki, on Saturday, commiserated with King Salman of Saudi Arabia, his countrymen and the world's Muslim community over the tragic loss of lives in Friday's crane collapse at the Grand Mosque, Mecca, which was at the time filled with worshippers.

Buhari directed the Ministry of Foreign Affairs and the Nigerian Embassy in Saudi Arabia to closely monitor developments and ensure the safety of all Nigerian pilgrims in that country.

A statement by presidential spokesman, Garba Shehu, said Buhari also urged all Nigerians to pray for the continued safety of their compatriots currently in that country for this year's Hajj. The President prayed for the repose of the souls of those killed in the incident, which occurred only about an hour before evening mahgrib prayers on the Muslim weekly day of prayer and grant the injured speedy recovery.

On his part, Saraki, according to a statement from his media office, specifically bemoaned the tragedy and the attendant loss of lives and destruction, just two weeks to when thousands of Islamic faithful would gather at the holy mosque for this year's pilgrimage.

He called on the Saudi authorities and other relevant stakeholders to do everything necessary to ensure the safety of citizens and pilgrims in the holy city before, during and after the hajj exercise. "My heart goes out to those who lost their lives. I pray for quick recovery for the injured," Saraki added.

Meanwhile, Saudi authorities have ordered investigations into the crash of the huge red crane, which officials say was caused by strong winds and heavy rains. Reports quoted the head of Saudi's civil defence agency, Lt Sulayman Bin-Abdullah al-Amr, as saying the probe would assess the damage, and the "extent of the safety of these sites."

The Grand Mosque, known as the Masjid al-Haram, is the largest mosque in the world and surrounds Islam's holiest place, the Kaaba.

At least 107 people, including Indonesian, Indian, Iranian and Egyptian citizens, were killed, while 230 others were injured in the incident that occurred at 17:23 local time (14:23 GMT) on Friday.

BBC quoted Essam al-Ghalib, a Jeddah-based journalist, as saying the crane fell through the outer ring of the Grand Mosque and punctured through the roof, sending down tonnes of cement and debris onto people either praying or walking through.

Up to two million people are expected to arrive in Mecca for the Hajj from all over the world on September 21.

A Saudi official said the hajj would proceed despite the tragedy, as "the affected part will probably be fixed in a few days," said the official, craved anonymity. Irfan Al-Alawi, from the Islamic Heritage Research Foundation, told the BBC that 15 large cranes undertaking major redevelopment work, currently surround the Grand Mosque.

"The entire area is like a salvage yard," Al-Alawi said. "Saudi Arabia has to re-think its health and safety strategy," he said, "as there were 800,000 people in the mosque area at the time of the accident."