BAGHDAD -- Two roadside bombs targeting Shiite pilgrims went off in different areas of Baghdad on Wednesday, leaving at least 20 people injured, local police source told Xinhua.

The source said 16 pilgrims were wounded by the first blast in New Baghdad district, southeastern Baghdad, while another roadside bomb blast in Fadheleh district in southern Baghdad wounded four people.Xinhua correspondents could clearly heard the sound of two blasts in central Baghdad when the incidents took place.

The attacks came a day after a series of mortar and bomb attacks on Tuesday that killed six Shiite pilgrims and wounded 40 others as thousands of them were travelling on foot across Baghdad streets heading to a holy shrine in Kadhmiyah to observe the major Shiite ritual, the climax of which will be on Thursday.

About one million pilgrims from many parts of Baghdad and other provinces are expected to gather near the Imam Mussa al-Kadhim shrine in Baghdad's northern district of Kadhmiyah for the annual commemoration of the death of the seventh of the most sacred 12 Shiite Imams.