Another 28 people were missing after the disaster on the Tigris in the city of Mosul, according to an interior ministry official who did not want to be named.

"The boat sank because there were too many passengers on board, more than a hundred," another security official based in Mosul told AFP.

The vessel was packed with men, women and children crossing the Tigris to go to a popular picnic area, he said.

The authorities had warned people to be careful after several days of heavy rains led to water being released through the Mosul dam, causing the river level to rise.