2006 Karbala–Ramadi bombings
On 5 January 2006, a series of suicide attacks were launched in the Shia holy city of Karbala and in Ramadi city centre, each killing about 60 or more. The bombings in Ramadi consisted of two suicide bombers detonating their bombs within minutes of each other.
Source: Wikipedia — 2006 Karbala–Ramadi bombings (CC BY-SA 4.0)