Child among three killed in blast on Baghdad's Sadr district

Three people were killed in an explosion at a market in Baghdad on Tuesday, including a woman and child according to a security source.

The blast struck in the Shia bastion of Sadr City, a sprawling district where authorities regularly carry out raids close to the busy market to seize illegal weapons.

"Three people were killed and four others injured in an explosion in a covered market near the Mreydi souk in Sadr City," Baghdad's military operations command said in a statement.

A source from the security services told AFP that a woman and a child were among those killed.

Authorities did not detail the cause of the blast and said an investigation would be launched.

The Mreydi souk is an important hub for illegal weapons sales and the area has seen years of violence since the US-led invasion of Iraq in 2003.

In June, at least 16 people were killed and some 30 injured in an explosion at a house in the area where weapons were stored.

Violence has fallen in Iraq and particularly Baghdad, which suffered numerous jihadist attacks, since the government declared victory over the Islamic State group in December.

But despite government forces retaking all of Iraq's towns and cities from IS, clandestine jihadist cells remain present, analysts say. 

‘Proto-state to covert terrorist network’

On Monday, UN report said the Islamic State group still may have up to 30,000 members roughly equally distributed between Syria and Iraq, and its global network poses a rising threat.

The report penned by UN experts said that despite the near-defeat of IS in Iraq and most of Syria, it is likely that a reduced "covert version" of the militant group's "core" will survive in both countries, with significant affiliated supporters in Afghanistan, Libya, Southeast Asia and West Africa.

The estimate of between 20,000 and 30,000 members includes "a significant component of the many thousands of active foreign terrorist fighters," it said.

While many IS fighters, planners and commanders have been killed in fighting, and many other fighters and supporters have left the immediate conflict zone, the experts said many still remain in the two countries — some engaged militarily "and others hiding out in sympathetic communities and urban areas."

IS fighters swept into Iraq in the summer of 2014, taking control of nearly a third of the country. At the height of the group's power its self-proclaimed caliphate stretched from the edges of Aleppo in Syria to just north of the Iraqi capital, Baghdad.

With its physical caliphate largely destroyed, the Islamic State movement is transforming from a "proto-state" to a covert "terrorist" network, "a process that is most advanced in Iraq" because it still controls pockets in Syria, the report said.

Read more: Syria: The making and unmaking of a refugee state

The experts said the discipline imposed by IS remains intact and IS leader Abu Bakr al-Baghdadi "remains in authority" despite reports that he was injured.

"It is just more delegated than before, by necessity, to the wider network outside the conflict zone," the experts said.

The flow of foreign fighters to IS in Syria and Iraq has come to a halt, they said, but "the reverse flow, although slower than expected, remains a serious challenge."