KARBALA, Iraq (Reuters) -- A bomb planted on a cart pulled by a motorcycle killed at least 20 people and wounded 110 others as Shi'ite pilgrims poured into the Iraqi holy city of Karbala today for a major religious rite, police said.
Shi'ite gatherings are frequent targets for Sunni Islamist militants such as Al-Qaeda, trying to stoke sectarian carnage, while recent months have also seen major coordinated attacks by suicide bombers on Baghdad ahead of a March election.
The toll from today's bombing could rise, police said.
Police said three people were killed and 21 wounded late on February 2 when a bomb attached to a military vehicle exploded in Karbala, 80 kilometers southwest of Baghdad.
On February 1, a bomb targeting Shi'ite pilgrims killed more than 40 people on the outskirts of Baghdad as they set off on the annual trek to Karbala for the Arbain festival.
Prime Minister Nuri al-Maliki has improved security across Iraq a central theme of his campaign for the March 7 parliamentary election and he has called on the security forces to ensure pilgrims heading to Kerbala are protected.
Millions of Shi'ites from Iraq, Iran, Bahrain, and other nations have defied the threat of bombings since the 2003 U.S.-led invasion toppled the Sunni-led government of Saddam Hussein to visit Iraq's Shi'ite holy sites.
Arbain marks 40 days of mourning for Hussein, the Prophet Muhammad's grandson, who died in a seventh-century battle at Karbala. Hundreds of thousands of pilgrims, beating their heads and chests in ritual mourning, visit the city for the rite.