A bombing against a Shiite hall in Baghdad killed 15 people Friday, among several attacks to strike Iraq with unrest at its worst since 2008 amid fears of a revival of all-out conflict.

Nationwide violence left 23 dead and dozens more wounded as bombings struck town squares and a husseiniyah, or Shiite religious hall, as the country grapples with a political deadlock and months-long protests by its Sunni Arab minority.

Analysts and diplomats worry that the standoff, which is often linked to levels of violence, is unlikely to be resolved at least until general elections due next year.

No group has claimed responsibility for the wave of attacks in Iraq in recent months, but Sunni militants linked to Al-Qaeda frequently target the country's Shiite majority, whom they regard as apostates.

Friday's deadliest attack struck the Husseiniyah Ali Basha in the Graiat area of north Baghdad, with a car bomb exploding near the Shiite religious hall at around 8:00 pm (1700 GMT).

At least 15 people were killed and 32 others were wounded, a police colonel and a medical source said.

The area, which runs adjacent to the Tigris river, is frequented by Baghdad residents, particularly on Thursday and Friday evenings, who visit its multitude of restaurants serving Iraq's most famous delicacy -- masgoof, or flame-grilled carp.

Elsewhere on Friday, bombs primarily targeting town squares killed eight people.

In Samarra, a predominantly Sunni town north of Baghdad, a suicide bomber detonated a car bomb near Al-Haq square, a focal point for anti-government protesters for months.

The attack took place just before mid-day Friday prayers near the Al-Razzaq mosque, killing seven people and wounding nine others, police and medics said.

The bomber wore an army uniform, police said.

And in the mostly Shiite town of Kut, south of Baghdad, a bomb set off in Al-Amil square at around 10:00 am (0700 GMT) killed one person and wounded 17 others.

Two militants also died in the northern town of Hawijah when the bomb they were trying to plant unexpectedly went off, officials said.

Iraq has seen a surge in violence since the start of the year, with the UN reporting more than 2,500 people killed from April through June, the highest such level since 2008.

Through five days of July, the number of dead already topped the number of people killed throughout all of December 2012, according to an AFP tally based on reports from security and medical officials.

The increase in unrest has coincided with ongoing protests in the Sunni Arab community that analysts and diplomats say have boosted recruitment to Sunni militant groups and given them room to manoeuvre.

Iraqi political leaders have vowed to resolve outstanding disputes, with Prime Minister Nuri al-Maliki meeting with his two main rivals last month in a bid to ease tensions, but no tangible measures have been announced.

Outgoing UN special envoy Martin Kobler has pushed for greater dialogue and a resolution to the disputes, warning that the "carnage" must be stopped.