Baghdad ? Two bombs went off within minutes of each other in a crowded shopping district in the capital Thursday, killing at least 53 people and wounding 130 – a reminder that deadly attacks are a daily threat even though violence is down.

There were no immediate claims of responsibility. But back-to-back bombings – designed to maximize carnage – became the hallmark of attacks on civilians by al-Qaida in Iraq during the worst of the violence in Baghdad in 2006.

Like in previous such attacks, the tactic seeks to draw in the people with the first blast before a second bomb detonates.