KADHMIYAH, Iraq: Millions of mourning pilgrims have headed on foot to the twin-domed holy shrine of Al-Imam Mussa bin Jafar Al-Kadhim (AS) and his grandson Al-Imam Muhammad Taqi Al-Jawwad (AS) to commemorate Rajab 25 which marks the martyrdom anniversary of Al-Imam Al-Kadhim (AS), the seventh in fallible descendant of Prophet Muhammad (S), undaunted by scorching sun, and waves of attacks that left more than 90 mourners martyred.

Pilgrims, who were searched at multiple checkpoints on their way to Kadhimiyah, wound through the streets in their thousands under a blistering sun, repeating religious chants, with beating their chests in a sign of mourning for the imam.

Tents along the way provided the pilgrims with free food and water, while some people set out small machines along the road that sprayed mist on the pilgrims to cool them as they passed.

Long lines of pilgrims, many wearing green headbands, the colour of Islam, and some carrying green flags with the image of Imam Kadhim, were seen in the Kadhimiyah area walking towards the shrine.

"This is the sixth year I have come ... I left home around 2am and I feel so good now," said Hussein Murawih, 17, who walked from Suwayrah, some 60 kilometres southeast of Baghdad.

"We just came to tell the terrorists that we are against you. We are not afraid of the explosions or of terrorism. Visiting Imam Kadhim is a great thing because we want to express condolences to the imam."

Another pilgrim also brushed off Wednesday's killings.

"The explosions mean nothing for us. It is not something new. Even if 20 car bombs exploded every day, does that mean we will stop walking to the imam? No," said Salam Jaber, 27.

"I have been walking for five days," said Jaber, who came from the town of Muwafaqiyah, some 180km southeast of Baghdad.

Iraqi authorities banned motorcycles from Baghdad’s streets and dispatched tens of thousands of security forces to guard the pilgrimage.

“The events that took place yesterday will never undermine our determination to go to commemorate Imam al-Kadhim,” vowed pilgrim Sayid Ali Jassim, standing near a security checkpoint where heavily armed soldiers peered out from behind barriers.

Main Baghdad streets were closed off with concrete blocks Thursday, and soldiers at roadblocks searched pilgrims as they entered roads leading to the shrine.

A senior Defense Ministry officer said motorcycles had been banned to reduce the risk that one might slip a bomb past a checkpoint, and he said at least 30,000 soldiers and police were on the streets.

He spoke on condition of anonymity to discuss the measures.

The commemoration climaxes on Saturday.