In 2015, Kata'ib al-Imam Ali began to send its fighters to Syria, allegedly to protect the Sayyidah Zaynab Shrine, and participated in the Second Battle of Tikrit. In early 2016, its fighters were involved in the Syrian government offensive to reconquer Palmyra and Tadmur from ISIL, and later that year, Kata'ib al-Imam Ali took part in the Battle of Mosul and the Aleppo offensive (November–December 2016).