A wave of attacks in Iraq, including a series of coordinated car bombs in Baghdad, killed 46 people Wednesday as militants took more territory from security forces in crisis-hit Anbar province.

The twin setbacks for authorities grappling with Iraq's worst period of unrest since the country emerged from a sectarian war that killed tens of thousands come just months before landmark parliamentary elections.

Diplomats including UN chief Ban Ki-moon have urged Iraq's leaders to seek political reconciliation to resolve nationwide violence and the standoff in Anbar, but Prime Minister Nuri al-Maliki has ruled out dialogue with militants as his forces have launched wide-ranging security operations.

But the operations, which authorities say have led to the killing and capture of several militants affiliated with the Al-Qaeda-linked Islamic State of Iraq and the Levant, have not stopped the bloodshed.

Attacks in Iraq on Wednesday killed 46 people and wounded dozens more, security and medical officials said, with most of the violence concentrated in Baghdad.

Seven car bombs went hit civilian targets in majority-Shiite or confessionally-mixed neighbourhoods of the capital, killing 24, with one targeting a packed market in the Baghdad neighbourhood of Shaab, and another detonating in front of a restaurant on Sanaa Street.

The blast on Sanaa Street killed three people and badly damaged the restaurant and nearby shops and cars, an AFP journalist said.

Windows of nearby shops were shattered, the restaurant's ceiling partially caved in, and blood and mangled vehicle parts were scattered around the scene.

A suicide bombing at a funeral in the town of Buhruz, in the restive and religiously-mixed Diyala province north of Baghdad, also killed 16 people and wounded 20 others, officials said.

The funeral was for a member of the Sahwa, the Sunni tribal militias who sided with the US military from 2006 against their co-religionists in Al-Qaeda, helping turn the tide of Iraq's violent insurgency.

As a result, the Sahwa, or Awakening, are often targeted for attacks by Sunni militants who see them as traitors.

Six other people, including three soldiers, were killed in attacks in and around the northern city of Mosul.

Government loses ground in Anbar

In Anbar province in the west, meanwhile, Iraqi forces lost more ground as Sunni gunmen, including those linked to Al-Qaeda overran two key areas when police abandoned their posts.

The losses mark a second day of setbacks for government forces and their tribal allies as they try to retake territory on the capital's doorstep from militants who hold all of the former insurgent bastion of Fallujah and parts of the nearby Anbar provincial capital Ramadi.

The crisis marks the first time militants have exercised such open control in major cities since the height of the insurgency that followed the US-led invasion of 2003.

"We gave ourselves up, and we gave up our arms to Daash," one policemen, who did not want to be named, told AFP from the town of Saqlawiyah, referring to the commonly-used Arabic name for the Al-Qaeda-linked group ISIL.

"They have very heavy arms, which are much stronger than what we have. Our police station was not very well protected, and they surrounded us. Even when we called for support, nobody came. Now, some of us have gone home, others have gone to other police stations."

Militants overran the police station in Saqlawiyah, a town just west of Fallujah, and took control of the entire area after using mosque loudspeakers to urge policemen to abandon their posts and their weapons.

They also retook the station and surrounding neighbourhood of Malaab, a major district in Ramadi, after security forces trumpeted their successes in the area just days earlier.

Clashes, meanwhile, erupted periodically in Ramadi and on the outskirts of Fallujah from Tuesday evening into Wednesday morning, security and medical officials said, with two children killed, and 13 other civilians wounded in the violence, according to doctors.

Fighting erupted in the Ramadi area on December 30, when security forces cleared a year-old Sunni Arab anti-government protest camp.

The violence spread to Fallujah, and militants moved in and seized the city and parts of Ramadi after security forces withdrew.