TIKRIT: Militants shot dead 14 Shia tanker drivers after checking their identity papers at a makeshift roadblock on the main route leading north from the Iraqi capital late on Wednesday, police said.
The killings took place near Sulaiman Pek, 160 km north of Baghdad, following clashes inside the town between militants and the police and army.
Sunni have been regaining momentum in their insurgency against the Shia led government in recent months, invigorated by the civil war in neighboring Syria, which has inflamed sectarian tensions in Iraq and the wider region.
"All the victims were Shiia tanker drivers who were coming from Baghdad to Kirkuk," Talib Mohammed, the town's mayor, told Reuters by phone. "Militants blocked their way near Sulaiman Pek, checked their IDs and executed them by shooting them in the heads and chest."
Earlier, gunmen ambushed a minibus in western Tikrit, 150 km north of the capital, shooting dead four soldiers who were travelling on the road from Baghdad to Mosul.
Nine policemen were also killed when militants riding on pickup trucks opened fire of a checkpoint in Shura, 50 km south of Mosul, Iraq's third largest city and capital of the Sunni dominated Nineveh province.
The steady deterioration of security in Iraq was highlighted by a mass jailbreak near the capital on Sunday when around 500 convicts, including senior al Qaeda operatives, escaped after militants attacked two prisons.
The Islamic State of Iraq and the Levant, which was formed through a merger between al Qaeda's Syrian and Iraqi branches, claimed responsibility for the raids and said it had freed its jailed comrades after months of preparation.
One security official told Reuters on Tuesday that some of the escaped inmates were heading to Syria to join the ranks of the mainly Sunni rebels fighting to overthrow President Bashar al Assad, whose Alawite sect derives from Shia.
Shia fighters from Iraq have also joined the conflict on Assad's side, along with Lebanese militia Hezbollah.
Insurgents in Iraq have been recruiting from the country's Sunni minority, which increasingly resents Shia domination since the US led invasion that toppled dictator Saddam Hussein in 2003.
More than 720 people have been killed in militant attacks in Iraq so far in July, according to violence monitoring group Iraq Body Count.
Three roadside bombs in the volatile, ethnically mixed city of Kirkuk wounded several people and a car bomb explosion near a market in the town of Tuz Khurmato wounded three on Wednesday.