Baghdad, Iraq (CNN) -- Hundreds of thousands of Shiite pilgrims will celebrate the Shaabaniya religious holiday on Wednesday, undeterred by two car bombs that killed at least 25 people two days earlier.
Most of the victims were pilgrims. The bombs exploded on a road between Karbala and Najaf.
The holiday celebrates the birth of Imam Mohammed al-Mehdi, the 12th Shiite imam, who disappeared in the 9th-century.
Shiites call him the "hidden imam" and believe he will return to restore peace and harmony.The annual Shiite pilgrimage has been a regular target of insurgents.
Last year, at least five people were killed in a car bomb that targeted pilgrims. The attack on the pilgrims, which wounded 20 others, happened in Iskandariya, about 40 kilometers (25 miles) south of Baghdad.