At least eight people have been killed in three near simultaneous blasts in the Iraqi city of Karbala, police and medical officials have said.

The first blast struck around the time of evening prayers on Wednesday, close to one of the Shia holy city's two major shrines, a police official said.

Two more explosions followed soon after at the second shrine.

"The attacks took place near the shrines of al-Abbas and al-Hussein," Mohammed al-Mousawi, a resident of Karbala, told Al Jazeera.

Several buildings were damaged and a number of cars were reported to be on fire.

Police said at least 40 people have been wounded in the blasts.

The casualties have been confirmed by an official at the Karbala hospital.

Iraq has seen a dramatic drop in violence over the past 18 months since the US committed thousands of extra troops to shore up its efforts in the country, but attacks are still common.