A roadside bomb attack targeted a Baghdad suburb Monday, killing at least 18 people and wounding dozens of others at a crowded market, two Iraqi security officials said.

The attack took place in Sadr City, the officials said. They spoke on condition of anonymity in line with regulations. It happened a day before the Eid al-Adha holiday when the market was busy with shoppers.

Piles of merchandise lay on the ground after the explosion. Shopkeepers recounted to security forces how the blast had occurred as they salvaged what items they could.

There was no immediate claim of responsibility but the Islamic State group has claimed similar attacks in the area before.

Prime Minister Mustafa al-Kadhimi placed the commander of the federal police regiment responsible for the area of the market place under arrest, according to an Iraqi military statement. It also said an investigation was launched.

It was the third time this year that a bomb hit a market in the densely populated neighborhood. In April, at least four people were killed in a car bomb attack in Sadr City. That blast was caused by an explosive device attached to a parked car at the market.