At least 45 Iraqi police officers have been killed in an attack by Islamic State (IS) militants in Anbar province, security officials say.
Suicide bombers rammed three vehicles packed with explosives into a base in the Tharthar area, on a road connecting the cities of Falluja and Samarra.
Several high-ranking officers were among the casualties, one source said.
Anbar has been the scene of fierce fighting between pro-government forces and IS militants in recent weeks.
A volunteer force of mostly Iranian-backed Shia militias has launched an operation to regain control of the provincial capital, Ramadi, which fell to IS last month.
A security source in the Anbar Operations Command said that three explosives-laden armoured Humvees captured by IS were used in Monday’s attack on the headquarters of the 3rd Battalion of the Iraqi Federal Police’s 21st Brigade.
The bomb blasts caused a large explosion at an ammunition depot inside the base.
Several senior officers were killed and the commander of the 9th Brigade, Brig Gen Moussa Haider, was among the 33 wounded, the source added.
A doctor told the AFP news agency that the bodies of at least 37 people had been brought to Samarra hospital.
Security forces reportedly regained control of the facility from IS several days ago and were using it to launch operations aimed at cutting IS supply lines from Samarra, in neighbouring Salahuddin province, to Anbar.
Separately, a senior security source in Anbar said the “final touches” were being put to a plan to drive IS out of Ramadi and that it would begin within days.
The source said six Iranian-made Zelzal-2 rocket launchers had been transported to the frontline in Anbar. The Zelzal-2 fires unguided rockets carrying 600kg (1,320lb) warheads and has a range of 100 to 300km (60-185 miles).
Three-thousand fighters had also completed basic training near Habbaniya military base, east of Ramadi, in preparation for the assault on the city, the source added.