Intra-Shiite conflicts have continued in Iraq, with pro-Iran and pro-Iraq factions firing at each other in Basrah City on Thursday.

Footage shows gunfire and explosives ringing out in the Corniche Street area of the city, reportedly near a base of the Iran-affiliated Asa'ib Ahl al-Haq paramilitary, on September 1.

Local sources said several Asa'ib fighters have been arrested by members of Saraya al-Salam, an armed group linked to influential Iraqi nationalist politician Muqtada al-Sadr.

Al-Sadr announced his withdrawal from politics on Monday, prompting his loyalists to stage bloody protests on the streets. His followers stormed Baghdad's Green Zone, with the chaos reportedly spreading to cities in the south.

Medical officials told local media that at least 15 people have died in the fighting while 350 more were injured.

Before his withdrawal, Al-Sadr's supporters had been staging sit-in protests outside the parliament complex in Baghdad to install him as Iraq's premier after months of political gridlock that has left the country without a government.

The nationalist cleric and his faction were reportedly opposing the nomination of Mohammed Shia al-Sudani for the post as they believed he was 'too close' to Iran.