Some 10 blasts were heard in the sprawling area in central Baghdad at 6 am, and helicopters buzzed overhead. The US public address system there warned people to “duck and cover” and to stay away from windows.
The deadliest attack was in the main northern city of Mosul where a suicide bomber crashed an explosives-laden truck into an Iraqi army base, triggering a blast that killed 10 soldiers and wounded 30 other people, mostly soldiers, said  Major Mohammed Ahmed.
“The bomber smashed the truck through barriers at the entrance to the base and triggered the explosion” at around 7:00 am,” said Ahmed.
Iraqi and US troops are engaged in a major offensive against Al-Qaeda in Mosul, which according to US commanders is the jihadists' last urban stronghold in Iraq.
In a brutal attack in the south of Baghdad, armed men travelling in three cars opened fire on crowds in a local market in the mixed Zafaraniyah neighbourhood, killing seven people and wounding 16, security and medical officials said.
In another attack in the Iraqi capital, a Katyusha rocket struck a residential building in largely Shiite eastern Al-Kamaliyah neighbourood, killing at least five people and wounding eight, security officials said.
A car bomb near a bus stop in Baghdad’s Shiite Al-Shuala neighbourhood killed five people and wounded eight others, security officials said.
Further north, a roadside bomb near the town of Al-Tuz, 75 kilometers south of Kirkuk, killed four Iraqi army personnel.