Some 2.5 million Iranians are expected to take part in this year’s Arba’een pilgrimage in the holy city of Karbala in Iraq, an Iranian official said.

Millions of Iranian nationals travel to Iraq annually to attend the pilgrimage, known as Arba’een, which marks the end of a 40-day mourning period that commemorates the martyrdom of Imam Hussein (AS), the grandson of the Prophet Mohammed (PBUH).

Mohsen Nezafati, a senior Iranian pilgrimage official, said while 2 million Iranians took part in the Arba’een march last year, this year’s figure is expected to reach 2.5 million.

Calling Arba’een event the largest gathering of the world’s Shia Muslims, Nezafati said the pilgrimage also serves as a massive political maneuver.

“Given the Takfiri terrorists’ active presence in the region over the past years, Arba’een pilgrimage has gained more momentum,” he added.

He also said that the presence of such a huge number of Iranian pilgrims in Karbala each year is not possible without close cooperation between Iran and Iraq.

Iran's Police Chief Brigadier General Hossein Ashtari also said that in addition to Shalamcheh, Chazabeh and Mehran borders, Iran is able to open Khosravi border for Arba’een pilgrims.

Ashtari added that the Khosravi border will be open provided the Iraqi government meets the necessary requirements.