At least 16 people were killed and more than 50 wounded Friday morning when a bomb exploded at a Sunni mosque in the hometown of former Iraqi leader Saddam Hussein.
Investigators say the blast took place as worshippers were leaving the mosque in Tikrit, a city about 130 kilometers north of Baghdad.
The mosque is part of a series of palace grounds built during the Hussein era.
The violence took place a day after at least nine people were killed in a series of explosions that rocked the western city of Ramadi.
Investigators says least two of Thursday's blasts occurred in a market that is near government offices.