Two suicide bombers have blown themselves up in and around a Shia mosque in the Iraqi capital, killing 26 people and wounding many more, police said.

Tuesday's coordinated blasts are the latest in a string of attacks rippling across Iraq that is reviving fears the country is headed back toward the widespread sectarian bloodshed that pushed it to the brink of civil war in 2006 and 2007.

Police said the first bomber detonated his explosives at a security checkpoint near the mosque in Baghdad's northern al-Qahira neighbourhood in an apparent attempt to distract the authorities.

The district is a middle-class, Shia-majority neighbourhood.

Amid the commotion, a second bomber slipped into the mosque and blew himself up while worshippers were performing midday prayers, according to police.

A medic in a nearby hospital confirmed the casualties. All officials spoke on condition of anonymity because they were not authorised to speak to media.

There was no immediate claim of responsibility.

The latest violence comes a week after a series of blasts across the country left at least 48 people dead.

More than 1,000 people were killed in attacks in Iraq during May, according to the United Nations, making it the deadliest month since the 2006-2007 sectarian bloodletting.

Both Sunnis and Shias have been targeted in an intensifying wave of violence since the beginning of the year.