ERBIL, Kurdistan Region of Iraq – More than 600 people were hospitalized after experiencing breathing difficulties due to a chlorine gas leak in Karbala late Saturday, Iraq’s health ministry announced, adding that all the patients have now been discharged.

A statement from the health ministry on Sunday said that a total of 621 cases of breathing difficulties were recorded due to the gas leak, stressing that “all the injured received the necessary treatment and left the hospitals in good health.”

The ministry praised efforts of the medical staff and civil defense for dealing with the situation quickly and efficiently.

Iraqi interior ministry spokesperson Miqdad Miri said that the incident was caused by a chlorine gas leak from a water directorate on the Karbala-Najaf road, noting that the situation was controlled “without any significant repercussions.”

“The chlorine gas leak incident in the Karbala sewage project, which is unified between the provinces of Karbala and Najaf, has been brought under control,” read a statement from Karbala Governor Nassif al-Khattabi.

Millions of Shiite Muslims from around the world annually undertake a pilgrimage to the southern Iraqi city of Karbala to participate in Arbaeen, which marks the end of 40-days of mourning over the death of Imam Hussein, the grandson of Prophet Muhammad, who was killed in the deserts of Karbala in the seventh century.

Iraqi Interior Minister Abdul Amir al-Shammari on Friday announced that more than three million foreign visitors have so far arrived in Iraq to participate in Arbaeen pilgrimage ceremonies.

Arbaeen falls on August 15 this year.