Two bombs tore through worshippers gathering for prayers at a mosque in Iraq on Friday, killing 18 people, while three died in other attacks, officials said.

Two bombs tore through worshippers gathering for prayers at a mosque in Iraq on Friday, killing 18 people, while three died in other attacks, officials said.

The bombs, which hit the Musab bin Omair mosque near Samarra, north of Baghdad, also wounded 21 people, police and a doctor said.

"A huge explosion happened, and everything around us was thrown in the air," a number of injured confirmed.

Militants have carried out numerous attacks on mosques this year, raising fears of a return to all-out sectarian conflict, which peaked in 2006-2007 and killed thousands of people.

Also on Friday, mortar rounds killed a young girl west of Samarra and wounded two members of her family.

And gunmen kidnapped and killed a soldier in the northern province of Kirkuk, while a roadside bomb north of the city of Baquba killed one person and wounded three.

Violence in Iraq has reached a level not seen since 2008, killing more than 4,200 people since the beginning of the year.