The PMU, also known as Hashd al-Sha’abi, said its explosives teams managed to find and discover the weapons, INA reported.
The PMU teams were tipped by a number of citizens who reported strange devices having been left behind a Moukeb (resting place for Arbaeen pilgrims).
With the cooperation of the Iraqi Civil Defense, the mortars and mortar shells were delivered to the intelligence department of Karbala, it added.
The PMU also said it has strengthened its presence in several areas in the country to ensure the safety and security of Arbaeen pilgrims.
Meanwhile, Iraq’s national security apparatus announced that its forces have arrested 8 extremists in Najaf governorate.
It said they are members of an extremist religious group and threatened security and peace.
In other news, Iraq’s federal police commander said police forces have been deployed to Baghdad, Najaf and Karbala to serve and ensure the security of pilgrims during the Arbaeen procession.
There is good coordination between police and other security forces in Iraq in implementing the overall security plan for Arbaeen, he added.
The Arbaeen mourning ceremony is one of the largest religious gatherings in the world.
It marks the 40th day after Ashura, the martyrdom anniversary of the grandson of Prophet Mohammad (PBUH), Imam Hussein (AS). This year’s Arbaeen falls on September 17.
Each year, a huge crowd of Shias flock to Karbala, where the holy shrine of Imam Hussein (AS) is located, to perform mourning rites.
The pilgrims, mainly from Iraq and Iran, travel long routes on foot to the holy city.