Attacks mostly targeting Sunni Arab areas of Baghdad as well as northern and western Iraq killed at least 23 people on Tuesday, the latest in a months-long surge in bloodletting.

The rise in violence, which has killed more than 6,200 people this year, has prompted the authorities to appeal for international help in combating militancy ahead of general elections due in April.

Officials have blamed a resurgent Al-Qaeda emboldened by the civil war raging in neighbouring Syria, but the government has itself faced criticism for not doing enough to address the concerns of Iraq's disaffected Sunni Arab minority.

Shootings and bombings on Tuesday hit west Baghdad, as well as the predominantly Sunni cities of Abu Ghraib, Fallujah, Baquba, Tikrit, Samarra, Mosul and Tarmiyah.

In the deadliest attack, twin roadside bombs exploded near municipal offices in Tarmiyah, a town just north of Baghdad that has seen multiple deadly attacks in recent weeks.

When onlookers gathered at the scene, two suicide bombers blew themselves up. Militants in Iraq often carry out delayed attacks targeting first responders who rush to the scene of an initial bombing.

Overall, nine people were killed and 17 wounded, two security officials said.

Violence elsewhere in Iraq left 14 people dead and dozens more wounded, security and medical officials said.

A car bomb in Bayaa, a predominantly Shiite neighbourhood of west Baghdad, killed six people, while five more were wounded by a blast in mostly Sunni Amriyah district.

Attacks in Abu Ghraib and Fallujah, west of the capital in Anbar province, killed three people, while bombings in Mosul and in and around Baquba killed three more.

Two policemen were also killed in a coordinated attack on a welfare centre for policemen in the Sunni Arab city of Tikrit in which a car bomb was followed by clashes between militants and security forces.

The toll could have been much higher, officials said, but security forces managed to kill two would-be suicide bombers in the Tikrit attack.

The authorities have made some concessions aimed at placating Sunnis, including freeing prisoners and raising the salaries of anti-Al-Qaeda fighters, and have also trumpeted security operations against militants.

But daily attacks have shown no sign of abating.

More than 6,200 people have been killed this year, despite numerous checkpoints in Baghdad and the near-ubiquitous presence of security forces, with attacks hitting targets ranging from cafes and football grounds to soldiers at checkpoints and government officials in their cars.

"Measures taken by the government so far have not matched the importance of the issues," said Issam al-Faili, a professor of political history at Mustansiriyah University in Baghdad.

"The situation in Iraq is getting serious... and what the government is doing now is nothing radical, but only minor fixes."

Diplomats, analysts and human rights groups have argued for months that Prime Minister Nuri al-Maliki, a Shiite Arab, must reach out to the country's Sunnis and start work to reform anti-terror laws and rules barring members of executed dictator Saddam Hussein's Baath party from participating in public life.

They also say security forces must stop using heavy-handed tactics in Sunni areas of Baghdad and western and northern Iraq, such as mass arrests and the closing off of entire neighbourhoods.

Analysts say that while most Sunnis do not actively support Al-Qaeda, a lack of faith in the government may persuade them to stop cooperating with the authorities in their efforts to combat the jihadist network's Iraqi affiliates.