The death toll from a truck bomb targeting pilgrims after the conclusion of annual mourning rituals for a revered figure in Shiite Islam has risen to 23, an official said on Friday.

A further 49 people were wounded in the Thursday evening attack in the town of Musayyib, which lies about half-way along the main route linking Baghdad and the shrine city of Karbala where millions of worshippers have attended Arbaeen commemoration ceremonies in recent days.

The blast struck in a car park in Musayyib used mainly for vehicles transporting pilgrims.

The new figures were given by Hamed al-Milli, a councillor in Babil province, in which Musayyib lies.

Among the casualties were women and children.

Two separate roadside bombs in east Baghdad, one Friday morning and the other Thursday evening, each wounded eight Shiite pilgrims, officials said.

No group immediately claimed responsibility for the attacks, but Sunni militants often try to target Shiites during commemoration rituals in a bid to incite sectarian bloodshed.

The violence came despite a massive security operation involving some 35,000 soldiers and police, mounted to safeguard the millions of Shiite Muslims travelling to and from Karbala for the conclusion of Arbaeen.

Arbaeen marks 40 days after the Ashura anniversary commemorating the killing of Imam Hussein, a revered figure in Shiite Islam, by the armies of the caliph Yazid in 680 AD.