Muqtada al Sadr. Click to view.

BAGHDAD, IRAQ: The cease-fire extension issued by Muqtada al Sadr, the leader of the Iranian-backed Mahdi Army, appears to be in jeopardy after the Iraqi government has launched an offensive against the Shia terror group in the southern city of Basrah. Dubbed Operation Knights' Assault, Iraqi security forces have gone on the offensive to wrest control of the strategic oil hub and Iraq's second largest city from Mahdi Army control. The fighting has spread to Baghdad and the southern provinces.

Knights' Assault is an Iraqi-led operation and was ordered directly by Prime Minister Nouri al Maliki, who is in Basrah to direct the operation along with Interior Minister Jawad Bolani. Basrah has seen an uptick in Iranian-backed terror activity since the British withdrew from the city late last year. Political assassinations and intimidation campaigns have been on the rise as the Iranians work to extend their influence in the oil-rich city.

At least 18 Iraqis were killed, including three policemen, and more than 100 were wounded in fighting in the southern city on Tuesday, as Iraqi troops advance to clear neighborhoods controlled by the Mahdi Army. Fighting is reported to have broken out in Baghdad and Al Kut in Wasit province. Curfews have been imposed in Karbala, Wasit, Babil, Diwaniyah, Nasiriyah, and Basrah after fighting between the Mahdi Army and Iraqi security forces broke out in the South.

The Sadrist Bloc, the political arm of the Mahdi Army, has boycotted Parliament and called for general strike and civil disobedience. Muqtada al Sadr has not officially withdrawn from the self-imposed cease-fire.

Mahdi Army forces have also launched mortar and rocket attacks at US and Iraqi bases in Baghdad. On March 25, twelve mortar and rocket strikes were launched at the International Zone, Forward Operating Base Falcon, Forward Operating Base Rustamiyah, and Joint Security Stations Thawra 1 and SUJ. The attacks were launched from Sadr City, a Mahdi Army stronghold in Baghdad. On March 23, 15 civilians were killed during mortar and rocket attacks aimed at the sprawling Coalition military complex southern Baghdad.

US troops are acting in a support role in Basrah and the south, several US military officers told The Long War Journal. The US is providing intelligence, combat support, and air assets to back Iraqi security forces in Basrah and along the Iranian border.

US forces are also actively hunting the Mahdi Army cells in Baghdad conducting the mortar and rocket attacks. Coalition and Iraqi Army forces detained 11 Special Groups operatives believed to be behind a mortar attack on FOB Falcon.

The current Iraqi offensive has been in the works for some time. The Iraqi Army and police have been massing forces in the South since August 2007, when the Basrah Operational Command was established to coordinate efforts in the region. As of December the Iraqi Army deployed four brigades and an Iraqi Special Operations Forces battalion in Basrah province. The Iraqi National Police deployed two additional battalions to the province.

The clashes with the Mahdi Army come just weeks after Muqtada al Sadr admitted failure in Iraq. "So far I did not succeed either to liberate Iraq or make it an Islamic society — whether because of my own inability or the inability of society, only God knows," Sadr wrote to his followers. "The continued presence of the occupiers, on the one hand, and the disobedience of many on the other, pushed me to isolate myself in protest. I gave society a big proportion of my life. Even my body became weaker, I got more sicknesses."

Sadr declared an extension of his unilateral cease-fire on Feb. 22 after the US military and the Iraqi government brought significant political and military pressure on the Sadrist bloc and the "rogue" elements of the Mahdi Army. This decision caused sharp divisions inside the Sadrist movement and the Mahdi Army, with some politicians and military commanders vowing to fight the US military and the Iraqi government.

Sadr's Mahdi Army has been formed by Iran's Qods Force along the lines of Lebanese Hezbollah. Imad Mugniyah, the senior Hezbollah military commander who was killed in Syria in February, was among those behind the formation and training of the Mahdi Army. Iran established the Ramazan Corps to run weapons, fighters, and support to the Special Groups, which include significant elements of Sadr's Mahdi Army.