At least four explosions have hit separate areas in the Iraqi capital Baghdad, killing at least 37 people and injuring several others, police sources told Al Jazeera.

The first car bomb blast hit a crowded popular market in a predominantly Shia neighbourhood in Baghdad, killing at least 18 people, authorities said.



The explosion took place in impoverished neighbourhood of al-Bayaa in southwestern Baghdad, a police official said.

A double bombing in Al Shaab killed 8 others, including 4 soldiers.

And a fourth explosion in Shurtaa has killed another 11 people.

Al Jazeera's Imran Khan, reporting from Baghdad, said the car bomb at Bayaa district was "designed to kill as many civilians as possible."

No one has claimed responsibility for the latest attacks, but our correspondent said that the Islamic State of Iraq and the Levant (ISIL) has threatened to carry out more attacks in the Iraqi capital in recent days.

He said that the latest attacks have ignited fear in many neigbourhoods in the city.

Clashes in Fallujah

Earlier on Wednesday, at least 22 Iraqi soldiers and fighters from the Popular Mobilisation Forces have been killed in a double suicide car attack by ISIL in east Fallujah, local police sources have told Al Jazeera.

Wednesday's attack was carried out with a confiscated Iraqi army Humvee and an armoured army vehicle at the Harariyat village, part of Al Karmah town.

Both blasts targeted a congregation of Iraqi army soldiers and fighters.

At least 24 were also wounded in the incident.

The violence is part of ongoing clashes between ISIL and government forces, who have been cutting the supply lines of the armed group, isolating the cities of Ramadi and Fallujah.

"Iraq's security forces are taking towns and villages surrounding those cities and use them as staging posts to go into Ramadi and Fallujah," said Al Jazeera's Imran Khan.

Khan also said that Iraq's air force carried out an air strike in the centre of Fallujah, hitting a mosque that was allegedly housing ISIL fighters. At least 17 of the fighters were reportedly killed in the attack.

"However, we have spoken to the hospital sources who say that at least six civilians were killed in that attack," said Khan.

Our correspondent said Sunni residents of the targeted cities have reportedly been advised to move out as they might be mixed up with ISIL fighters and mistakenly targeted.

"One of the sources said that it doesn't matter even if they are women and children. If they are still in Ramadi, for example, at the time when the rival forces go in, they will be seen as ISIL supporters," Khan said.