A car bomb exploded in the Iraqi capital's busy Wathiq Square on Monday night, killing at least eight people and wounding 32, security and medical officials said.
Restaurants, a hotel and a tent used to serve water and tea to Shiite pilgrims are located in the square in the Karrada area of central Baghdad.
Hundreds of thousands of pilgrims are expected to travel to the shrine city of Karbala for next week's Ashura commemorations marking the death of Imam Hussein, one of the most revered figures in Shiite Islam.
The pilgrims have been targeted in the past, and the danger is higher than usual this year, with the Islamic State (IS) jihadist group holding large areas of Iraq that it has overrun since June.
IS and other Sunni extremist groups consider Shiites to be heretics and frequently target them in attacks.
Baghdad is hit by near-daily bombings and shootings, some of which have recently been claimed by IS.