Dubai: Two female suicide bombers detonated explosives outside a revered Shiite mosque in northern Baghdad on Friday morning, killing more than 75 people and intensifying a wave of attacks reminiscent of the ones that sparked widespread sectarian violence in 2006.

The attack was the deadliest single incident in Iraq since 63 people died in a truck bomb blast in Baghdad on June 17 last year, and came amid growing concern that a recent decline in violence might turn out to have been just a temporary lull.

The bombers targeted the mosque next to the tomb of Imam Mousa Al Kadhim in the Kadamiyah neighbourhood, where scores congregate each Friday morning for prayers.

A morgue official at the Kadamiyah Teaching Hospital said he counted 75 bodies but estimated the death toll could cross 100, because many of the bodies were dismembered.

A reporter saw at least 50 bodies in one of two morgue rooms, alongside a pile of severed heads and other body parts in plastic bags. More than 125 people were wounded in the blasts that took place within minutes of each other, police said. Many of the dead and wounded were Iranian visitors.

The attacks came a day after two suicide bombers detonated explosives in Baghdad and Diyala province, killing nearly 90 people in what was the deadliest single day of attacks this year.

Police said the attackers on Friday approached two gates to the shrine. "They used sidestreets to get there and this enabled them to avoid checkpoints. They blew themselves up in the crowd," Major General Jihad Al Jabiri, head of an Interior Ministry unit that investigates explosions.

He said the attackers placed two leather bags full of explosives among the crowds at the two main gates.