STORY: The protesters shot rifles and fired grenades toward a formation of armoured vehicles on the other side of a wall defending the Iraqi capital's fortified Green Zone.

Iraq's military said militants had also fired several rockets into the Green Zone.

Footage from the offices of the Badr Organization showed charred buildings and burnt out vehicles after Sadr supporters set fire to the structures, while pamphlets showing pictures of Iranian Supreme Leader Ayatollah Ali Khamenei lay strewn on the ground.

Badr Organization, which started as a Shi’ite paramilitary group supported by Iran in the 1980s, is led by Hadi al-Amiri. Badr makes up a big part of the Popular Mobilization Forces, the heavily armed Iraqi state paramilitary organization that contains dozens of Iran-backed factions. Amiri is a key leader in the Coordination Framework.

Nearly 20 people were killed on Monday (August 29) when clashes jolted Iraq into new violence as supporters of Sadr, a former anti-U.S. insurgent leader, faced off with Shi’ite armed groups mostly loyal to Iran.

A prolonged political deadlock after an October election, during which the two camps have competed for power, has given the country its longest run without a government and led to new unrest as Iraq struggles to recover from decades of conflict.

Sadr has positioned himself as a nationalist who opposes all foreign interference, whether from the United States and the West or from Iran. He commands a thousands-strong militia and has millions of loyal supporters across the country. His opponents, longtime allies of Tehran, control dozens of paramilitary groups heavily armed and trained by Iranian forces.