A suicide bomber detonated an explosive belt in central Baghdad on Tuesday morning, killing at least three people and wounding 27, security and medical officials said.

The ultra-radical militant group ISIS claimed responsibility for the bombing in an online statement.

The blast occurred near a gathering of workers in Tayaran Square, about a kilometer from a sit-in held by supporters of powerful Shi’ite cleric Moqtada al-Sadr to demand political reforms.

ISIS also claimed a suicide bombing last Friday that ripped through a trophy ceremony in Iskandariya, south of Baghdad after a football tournament killing 32 people and wounding 84.

At least 60 people were killed earlier this month in an attack further south, in Hilla, when an explosives-laden fuel tanker slammed into an Iraqi security checkpoint.

The country has been ravaged by a spate of suicide bombings in recent months targeting areas outside ISIS’s primary control in northern and western Iraq suggests that Iraqi government forces may be stretched thin after recent gains against the group.

A UN report estimated that more than 22,300 people have been killed or injured in armed conflict in Iraq in 2015.

Analysts in Europe have interpreted recent attacks there, such as last week’s bombings in Brussels or the killings in Paris last November, as an indication of ISIS expanding its field of action in response to setbacks in Iraq and Syria.

But Baghdad analysts say the group has long staged indiscriminate suicide bombings and see these attacks as a continuation of that tactic.