Iran’s Red Crescent Society announced Friday that at least nine Iranians who were on a pilgrimage to the Iraqi city of Karbala for a Shiite religious event have died.

Pir-Hossein Kolivand, the head of the Iranian Red Crescent Society (IRCS), said that more than 8,400 Iranian pilgrims have been treated or got an IV at the society’s makeshift clinics for cases such as extreme dehydration or low blood sugar in and around the Iraqi cities of Karbala, Najaf, and Kadhimiya. 

Social media is full of posts and videos of people complaining about the crowded border crossings with insufficient facilities. 

Mojtaba Khaledi, the spokesman for the Iranian Medical Emergency Organization, said on Thursday that over 10,300 pilgrims have been referred to healthcare stations with signs of heatstroke.

Three more Iranians died earlier in the week in Iraq's Wasit Governorate, which borders the Islamic Republic. 

Earlier in the day, Iraq and Iran closed land borders over safety concerns as millions of Iranian pilgrims supported by Tehran were on the move to reach Karbala for Arbaeen. The pilgrimage is on the occasion of Arbaeen, the 40th day after the death of the third Shiite Imam, Hussain Ibn Ali, who was killed in a power rivalry by the reigning caliph in a clash in Karbala in 680 AD.

Majid Mir-Ahmadi, the head of the Arbaeen pilgrimage headquarters, said that “in the wake of worrying incidents that happened at the Shalamcheh and Mehran borders and serious threats to the health and security of the pilgrims, high-ranking officials decided to close borders until further notice,” mentioning “a lack of proper infrastructure in Iraq for accepting the pilgrims” and “hot weather" as reasons behind the decision.