A website which has previously carried statements by al-Qaeda has said the organisation is waging a nationwide suicide bombing campaign in Iraq.
The site is often used by Abu Musab al-Zarqawi's Sunni Muslim militant group.
It claims the campaign is to avenge an offensive by US and Iraqi government troops on the northern town of Tal Afar.
The number of victims in a series of attacks today has been variously estimated at between 115 and more than 150.
Police sources in Baghdad said the number of people killed in a suicide bombing in the Shi'ite pilgrimage district of Kadhimiyah this morning has risen to 114.
It is the second worst bombing since the invasion of Iraq two and a half years ago. More than 160 people were injured. The bomb was on a minibus that was driven into a crowd of day labourers.
Separately, 11 people were killed in a suicide bombing in the Al-Adel district of west Baghdad.
Ten minutes later, a third bomber killed four civilians and injured 22 in the Shula neighbourhood of northwest Baghdad.
Gunmen also killed 17 people in Taji, a northern suburb of the capital. The victims are reported to have been dragged from their homes and shot dead.
