Iranian President Hassan Rouhani expressed condolences on Twitter Saturday to the families of the more than 700 people who were trampled to death Thursday during the annual hajj pilgrimage in Saudi Arabia. The tweet came as Tehran blamed Riyadh for the tragedy.

Ayatollah Mohammad Emami Kashani, a senior Iranian religious leader, called on the Saudis Friday to relinquish their management of the annual pilgrimage, which sees more than 3 million devout Muslims converging on a small area in the western Saudi city of Mecca to perform a five-day spiritual-cleansing ritual. His comments came a day after a stampede of pilgrims killed at least 769 people and almost two weeks after a construction-crane collapse killed more than 100.

“The Saudi government and authorities involved in hajj should appear before court and be held accountable,” the Press Association quoted Kashani as saying. “They should not lie and say, ‘It was because this or that, the weather was hot, it was the pilgrims’ faults.’”

Kashani said the Organization of Islamic Cooperation (OIC), an international group of Islamic countries, should take control over hajj logistics. The OIC is currently headed by Iyad bin Amin Madani, a Mecca-born former Saudi Arabian Airlines executive. He’s the first Saudi to serve as the head of the organization.

“The secretary general [Amin Madani] noted the enormous and continuous efforts of the Kingdom of Saudi Arabia in serving the pilgrims, ummrah performers and visitors, and its investments in the service of the Two Holy Mosques and the holy sites,” the OIC said in a statement Friday.

Meanwhile, the government of mostly Shiite Iran indicated Saturday it would take legal action against the government of mostly Sunni Saudi Arabia over the crush of the Muslim pilgrims at the hajj this year, with 136 Iranians among the dead, the Associated Press reported.