At least 700 pilgrims were killed and over 800 others injured in a horrific stampede at the annual Hajj pilgrimage in Saudi Arabia. The fatal stampede occurred Thursday during "stoning the devil," a Hajj ritual in Mina Valley, nearly two miles from Mecca, as HNGN reported previously. The tragedy struck during the Hajj pilgrimage on the first day of Eid al-Adha festivities.

Saudi King Salman announced an investigation into a stampede and crush as Saudi officials blamed "undisciplined pilgrims" for the tragedy.

"This sad accident, into which we have ordered authorities to launch an investigation and provide us with results as soon as possible, will not be allowed to degrade the great services we extend to the guests of God to perform their rituals," King Salman said, according to DW.

Iran's Supreme Leader Ayatollah Seyyed Ali Khamenei blamed Saudi Arabia for the tragedy.

"The Saudi government is obliged to accept its heavy responsibility in this bitter incident and meet its obligations in compliance with the rule of righteousness and fairness; mismanagement and improper measures that were behind this tragedy should not be undermined," Khamenei said, according to Sputnik News.

The deadly accident came two weeks after the crane crash tragedy at Mecca's Grand Mosque that killed more than 100 people, as HNGN reported previously. Around two million Muslims from around the world are taking part in this year's Hajj pilgrimage in the Saudi Kingdom.

Thursday's stampede and crush is the worst disaster to strike annual Hajj Pilgrimage in 25 years.