Iraq's equivalent of the Lebanese Hizbullah movement, Kata'ib Hizbullah, is without a doubt the strongest and most influential of all Shiite militias currently present in Iraq. This has come to be so mostly thanks to Iranian funding, lethal aid and the presence of Iranian advisors on the ground.
Iran has supplied these militias with anything from 12.7mm AM.50 anti-materiel rifles, 40mm Nasir grenade launchers, Safir jeeps equipped with 107mm multiple rocket launchers (MRLs), recoilless rifles and even 122mm HM-20 MRLs, all of which produced in Iran. The amount and type of weaponry supplied depends on the size of the militias in question.
However, the rumoured presence of Iranian tanks with militias in Iraq could until now not be confirmed. These rumours quickly made their way around the world each time any vehicle with tracks on a tank transporter driving close to the Western border of Iran was sighted. Now photograpic evidence has finally arisen of Iranian tanks that have joined the fight against the Islamic State in Iraq, and are busy driving their fighters out of the town of Tikrit.