A suicide bomber detonated an explosives-rigged Humvee armoured vehicle near security forces and allied militiamen south of Baghdad, killing at least 14, an officer and a doctor said Monday.

The blast took place on the northern edge of Jurf al-Sakhr, a large area south of the capital, where the government announced it retook the strategic town of the same name from the Islamic State (IS) jihadist group over the weekend.

Accounts of the attack, which also wounded at least 25 people, differed sharply.

Some sources insisted it took place on Sunday while others reported a similar attack in the same area on Monday.

There were also varying reports on the intended target of the attack, though most agreed it was against soldiers and Shiite militiamen.

Security forces and militia allies have fought for months to regain ground in Jurf al-Sakhr from IS, which spearheaded a major militant offensive that has overrun large areas since June.

The jihadists seized significant quantities of military equipment, including Humvees that have been used in suicide attacks on several occasions, as they swept security forces aside.

The expansive Jurf al-Sakhr area is strategic because of its location along the southern approach to Baghdad and on the way to Amriyat al-Fallujah, a town that has been hard-pressed by IS in recent weeks.

And Jurf al-Sakhr lies west of the main highway on which tens of thousands of Shiite pilgrims will travel in the coming days on the way to the city of Karbala for the annual Ashura commemorations.

Pilgrims taking part in the commemorations, which mark the death of Imam Hussein, one of the most revered figures in Shiite Islam, are often targeted with bombings during the annual rituals, which peak next week.

Karbala governor Aqil al-Turaihi has said that "Securing Jurf al-Sakhr is securing Karbala and the south completely, as the gateway to the south begins from Jurf al-Sakhr."

And holding it would also better position Iraqi forces to strike at militants in nearby Anbar province, where they have suffered a string of setbacks, prompting warnings that the entire province could fall.