An Iraqi security command said a suicide bomber detonated the explosives-rigged vehicle, while other officials said it was a car bomb.
At least 14 people were killed and at least 41 others wounded, security and medical officials said.
Turmoil in Iraq: Blast along Baghdad shrine route kills 23
They said several women and children were among the victims.
There was no immediate claim of responsibility for the explosion, but such attacks are usually carried out by the Islamic State group.
IS perpetrated a similar attack against pilgrims on the outskirts of Baghdad on Saturday, killing at least 23 people.
Many of the main thoroughfares in the city are closed in the days leading up to the annual commemoration of Imam Musa Kadhim's death, an important date in the Shia Muslim calendar.
Bombing against pilgrims kills 23 in Iraq as hundreds protest
Kadhim, the seventh of 12 imams revered in Shia Islam, died in 799 AD. The pilgrimage to his shrine in northern Baghdad has in recent years turned into a huge event that brings the capital to a standstill for days.
The main commemoration at the shrine in Baghdad's Kadhimiya neighbourhood will take place on Tuesday.
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