Hundreds of thousands of Shiite Muslim pilgrims are flocking to a Baghdad shrine to observe the death of a revered eighth century saint, snarling traffic and sending security forces to the streets to protect the worshippers.

Shiite pilgrims have been a favorite target of Sunni insurgents hoping to inflame sectarian tensions.

But no major attacks against the throng were reported so far on Tuesday morning. Eyewitnesses estimated the crowd number at hundreds of thousands.

Iraqi state TV said more than 3 million have visited the gold-domed Imam Moussa al-Kadhim mosque over the last few days.

Police used concrete blocks and razor wire to close roads across the capital to safeguard the pilgrims.