Shias from the southern and central regions of Iraq have begun their journey to Baghdad waving flags and chanting "Death to America! Death to Israel", in answer to Muqtada al-Sadr's call for a "million man march" in support of Lebanon's Hezbollah.
Sahib al-Ameri, a director of the Foundation for God's Martyrs, told reporters: "Thousands of Najaf people have set off for Baghdad as a response to Moqtada al-Sadr's invitation to take part."
The march comes at a tense time in the Iraqi capital when many are now beginning to talk of civil war. The Shias have an uneasy relationship with the US-backed government and security in the capital has been tightened.