Suicide bombings in cities north of Baghdad kill at least 25: Officials

Suicide bombers driving ambulances packed with explosives detonated their vehicles at a checkpoint and a car park for Shia pilgrims in two Iraqi cities on Sunday, killing at least 25 people and wounding dozens, officials said.

The twin attacks took place in Tikrit and Samarra, as Iraqi troops and security forces battled to retake the northern city of Mosul from Islamic State militants who have controlled it for more than two years.

They appeared to be part of a series of diversionary attacks by the militant group, which has struck the Kurdish-controlled city of Kirkuk, the capital Baghdad and a western desert town during the three-week Mosul campaign. 

In Tikrit, a bomber detonated his explosives-laden ambulance at the southern entrance to the city during the morning rush-hour, killing 13 people, police and hospital sources said.

Another attacker detonated a vehicle in a car park for pilgrims visiting one of Shia Islam's holiest shrines, al-Askari mosque in Samarra, south of Tikrit.

The bomb killed at least eight people, local officials said, including two Iranian pilgrims. The local operation command, a joint military and police unit, said the vehicle used in Samarra was also an ambulance.

Authorities in both cities declared curfews, fearing possible further attacks.

Iraq's elite Counter-Terrorism Service (CTS) pushed into the al-Karama area of eastern Mosul but faced heavy resistance and pulled some units back on Friday. CTS said its forces were again engaged in fierce fighting in east Mosul on Saturday.

Soldiers have also advanced toward the northern and southeastern edges of the city. Forces from Iraq's autonomous Kurdish region were active in the early days of the operation, but federal troops have since taken the lead in the fighting.

On the southern front, army and police forces have launched a multi-pronged attack on Hamam al-Alil, an area about 14km from the outskirts of Mosul, the military said.

The Popular Mobilisation Units (PMUs), an umbrella group for pro-government paramilitary forces that is dominated by Iran-backed Shia militias, are fighting southwest of Mosul in a bid to retake the town of Tal Afar, which lies between the city and Syria.