At least 21 people have been killed following apparently coordinated bombings in the Iraqi city of Tikrit.

The first blast took place as worshippers were leaving a Sunni mosque at the conclusion of Friday prayers. Investigators say 16 people were killed and more than 50 others wounded.

Hours later, a suicide bomber detonated explosives at Tikrit's main hospital, where many of the families of victims of the first blast had gathered. Officials say at least five people were killed and 10 wounded.

Tikrit is located about 130 kilometers north of Baghdad. It is the hometown of the late Iraqi leader Saddam Hussein. The mosque that was targeted Friday is part of a series of palace grounds built during the Hussein era.

Friday's bombings have taken place a day after at least nine people were killed in a series of explosions that rocked Iraq's western city of Ramadi.

Investigators says at least two of Thursday's blasts occurred in a market that is near government offices.