|Saturday's attack is Karbala's third in the last two days, amid annual Shia pilgrimage to the holy city
Several bombs have gone off in Iraqi cities, including Baghdad, killing at least five people and wounding several.
A parked car bomb targeting a night club killed two people and wounded nine others in central Baghdad on Saturday, police and hospital sources quoted by the Reuters news agency said.
A sticky bomb attached to a policeman's car went off near a checkpoint killing at least three people and wounding 15 others, mainly policemen, in eastern Kerbala, 80km south west of Baghdad, police and provincial council officials said.
Sources at the Karbala general hospital who spoke to Al Jazeera confirmed one death.
An annual pilgrimage has been going on Kerbala.
In other bombing news, armed men in a speeding car using weapons equipped with silencers shot at a police checkpoint and wounded three people, including two policemen, in Baghdad's southeastern Zaafaraniya district, an interior ministry source said.
Al Jazeera's Rawya Rageh, reporting from Baghdad, said the attack in the capital was aimed at the general public without specific targets.
Saturday's blast in Karbala was the third attack in the past two days on the holy city, as Shia pilgrims headed to visit the Imam al-Hussein shrine there to commemorate the birth of Imam Mohammed al-Mahdi.
The anniversary has become one of the annual pilgrimages that show strength for Iraq's majority Shia since the fall of Saddam Hussein in 2003.
Saddam Hussein banned Shia religious rites during his rule. Since his toppling, Sunni Islamists have frequently targeted Shias.
Unlike in previous years, the Shia pilgrimages in recent months have largely gone by without incident. But this year's pilgrimage in Karbala has been the target of repeated attacks.
On Friday, a car bomb exploded in a garage near a hospital west of Karbala, killing four people and wounding 20, police said.
Separately, a bomb placed under a parked car killed two people and wounded four others in northern Karbala on Friday, according to an army commander. A hospital source said the blast killed three people and wounded 23 others.
Last year, car bombs killed and wounded scores of people during the Imam Mahdi observance.