At least 12 people have been killed and 45 others injured in a bomb blast that targeted Shia pilgrims in the holy Iraqi city of Karbala.

"An explosive charge hidden at a pile of garbage near a road that leads to the holy shrine of Imam al-Hussein in Karbala detonated near crowds of Shia pilgrims," the Sharqiya television channel quoted a local police source as saying.

Iraqi security forces cordoned off the area where the explosion had taken place and ambulances rushed to transfer the victims to nearby hospitals.

The incident comes as hundreds of Shia pilgrims are pouring from various Iraqi provinces into the holy city in a bid to commemorate Arbaeen -- the 40th day after the martyrdom anniversary of Imam Hussein.

Imam Hussein is Prophet Muhammad's grandson who was killed in the battle of Karbala in 680 CE.

Terrorist groups in Iraq frequently target Shias and Sunnis to provoke sectarian violence in the oil-rich country.

MP/AA