Bombings in Iraq killed 20 people Sunday and brought the year's toll to more than 5,000 dead in a surge in violence that authorities have failed to curb, officials said.

Violence in Iraq has reached a level not seen since 2008, when the country was just emerging from a brutal sectarian conflict.

The spike in violence, which has included a number of sectarian attacks, has raised fears of a relapse into the kind of intense Sunni-Shiite bloodshed that peaked in 2006-2007 and killed tens of thousands of people.

On Sunday, 21 explosions -- 10 car bombs, nine roadside bombs and two suicide bombings -- hit central and south Iraq, also wounding 130 people.

In one of the deadliest attacks, a car bomb exploded near a bus station in the city of Kut, killing four people and wounding 15, police and medical personnel said.

Other targets in the wave of bombings included a football field and a funeral.

The funeral was for one of the victims of a car bomb targeting shoppers that killed 15 people in Samarra the day before.

Militants seeking to cause maximum casualties frequently bomb places where crowds gather, including shopping districts, markets, football fields, cafes, mosques and funerals.

Also on Sunday, Iraq launched a project to issue national IDs that are supposed to be more difficult to forge than current identification documents.

"Terrorist groups have always benefited from forged IDs, so we were sometimes forced to deploy experts... at security checkpoints to check the IDs," interior ministry spokesman Saad Maan said.

The ID project is just the latest in a string of security measures announced in recent months, but so far, none has curbed the violence.

Diplomats and analysts say the Shiite-led government's failure to address the grievances of the Sunni Arab minority -- which complains of political exclusion and abuses by security forces -- has driven the rise in unrest this year.

Violence worsened sharply after security forces stormed a Sunni Arab anti-government protest camp in northern Iraq on April 23, sparking clashes in which dozens died.

The authorities have made some concessions aimed at placating anti-government protesters and Sunnis in general, such as freeing prisoners and raising the salaries of Sunni anti-Al-Qaeda fighters, but underlying issues remain unaddressed.

With the latest unrest, more than 290 people have been killed this month, and over 5,000 since the beginning of the year, according to AFP figures based on security and medical sources.