As many as 40 people are believed to have died after a bomb explosion at a joint US-Iraqi base at Tal Afar, near Mosul in northwest Iraq.
20 people were reported injured. The explosion appeared to have targeted Iraqi army recruits.
It may have been carried out by a suicide bomber strapped with explosives but it was not immediately possible to verify this.
Five policemen were injured when insurgents threw a grenade at their patrol in Mosul itself, earlier.
Meanwhile, it has been reported that 16 employees of the Baghdad trading company Al Saeed Import Export have been kidnapped.
Elsewhere today, a policeman and three civilians were wounded when a roadside bomb hit a police patrol in southern Baghdad.
Mortar rounds landed in four different districts of the capital, injuring two civilians.
And at least one person was killed and three injured when a car bomb exploded in the Sadr city slum area.
A mortar round landed on the Sadr office in Baquba, 65km north of Baghdad, injuring two guards.
Four people who work in the US military base near Tikrit, 175km north of Baghdad, were injured when gunmen attacked them while they were heading to the base.
