The bombing of the Askariya shrine in the Iraqi town of Samarra has sparked a wave of violence that some fear could ignite an all-out civil war in the country.
Eighteen Iraqis, including senior police officers, soldiers and civilians, have been killed in a series of attacks across the country, police say.
Four car bombs and attacks on three police stations in the central Iraqi town of Samarra have left at least 37 people dead and 62 wounded.