A suicide bomber struck in a Shiite-majority area of north Baghdad on Monday, killing at least 12 people, security and medical officials said, Al Arabiya reported.
The blast in Kadhimiyah, which is home to a revered Shiite shrine, also wounded at least 42 people, the officials said.
A police colonel said the bombing took place inside a restaurant at Kadhimiyah's Aden Square, while interior ministry and medical officials said the attack targeted the crowded square.
It is the second suicide bombing to hit the capital in three days. On Saturday, an attack inside a restaurant in the Baghdad Jadida district killed at least 23 people.
There was no immediate claim of responsibility for the Monday attack, but suicide bombings are a tactic almost exclusively employed by Sunni extremists in Iraq, including militants of the Islamic State of Iraq and Syria group.
ISIS spearheaded an offensive that swept through large areas north and west of Baghdad last June, and Iraqi forces are battling to regain ground with support from U.S.-led air strikes.