At least 22 people died and 25 others were wounded Thursday in a suicide attack on a military complex in downtown Baghdad, an Iraqi military spokesman said.

The attack did not involve a car bomb, as police has said earlier, but rather was the work of a man who detonated the explosive belt he was wearing, Saad Maen said in a statement.

The blast occurred in front of an army recruitment center near the Al Muthana airport.

Security forces cordoned off the blast site and blocked traffic on adjacent streets.

It is not yet known which group staged the attack, but authorities are working with the hypothesis that the bomber was a member of the Al Qaeda-linked Islamic State in Iraq and the Levant.

Separately, a police official said that Iraqi security forces arrested four top ISIL leaders on Thursday.

The arrests came during a security operation in the western province of Al Anbar.

In addition, the source said that things are returning to normal in Fallujah and Ramadi, the largest cities in Al Anbar, as a result of the cooperation between the local tribal groups and police.

Iraq is experiencing a resurgence of political and sectarian violence that in 2013 took the lives of 8,868 people, of whom 7,818 were civilians, according to U.N. figures.

In the face of the increase in violence, the United States last Monday announced that it will accelerate the deployment of drones in Iraq to undertake monitoring duties and it is scheduled to send Hellfire missiles to the region this spring to equip the drones. EFE