* Bombs in Baghdad, village near Baquba
* Army in stand-off with Sunni Muslim militants
* PM says must avoid 'creation of evil statelets'
Bomb attacks hit the Iraqi capital Baghdad and a village near the northern town of Baquba on Wednesday, killing at least 52 people, police and hospital sources said.
In the deadliest incident, a bomb blew up in a funeral tent where mourners were marking the death two days ago of a Sunni Muslim pro-government militiaman, police said. It killed 18 people and wounded 16 in Shatub, a village south of Baquba.
Two years after U.S. troops left Iraq, violence has climbed back to its highest levels since the Sunni-Shi'ite bloodshed of 2006-2007, when tens of thousands of people were killed.
The army is locked in a standoff with Sunni militants who overran Falluja, a city west of Baghdad, more than two weeks ago in a challenge to Prime Minister Nuri al-Maliki's government.
They are led by the al Qaeda-linked Islamic State of Iraq and the Levant (ISIL), which is fighting in western Iraq and Syria to carve out a cross-border Islamist fiefdom.
"The battle will be long and will continue," Maliki said on state television on Wednesday, calling for world support. "If we keep silent it means the creation of evil statelets that would wreak havoc with security in the region and the world."
Maliki has ruled out an assault on Falluja by the troops and tanks ringing the city of 300,000, but has told local tribesmen to expel ISIL, which has exploited anger among minority Sunnis against a government they accuse of oppressing them.
Al Qaeda loyalists are pursuing a relentless campaign of attacks, mostly aimed at security forces, Shi'ite civilians and Sunnis seen as loyal to the Shi'ite-led government.
Half a dozen car bombs exploded across the Iraqi capital on Wednesday, mostly in Shi'ite districts, killing 34 people and wounding 71, police and medics said.
The Baghdad bombings followed attacks that killed at least 24 people the day before, as well as coordinated assaults by militants on a highway bridge and police station near Falluja.
A suicide bomber in an explosives-laden fuel tanker blew it up under the bridge near the town of Saqlawiya, about 10 km (six miles) north of Falluja, causing the bridge to collapse and destroying one of two army tanks parked on top, police said. Gunmen then attacked and destroyed the second tank.
Simultaneously, dozens of militants stormed a police station in Saqlawiya, forcing its occupants to surrender. Army helicopters later attacked the gunmen in the police station.
The wrecked bridge spans the main highway leading west from Baghdad across the vast Sunni desert province of Anbar towards Syria and Jordan. Police said the truck bomber had driven from Ramadi, the provincial capital of Anbar.