BAQUBA, Iraq (Reuters) - Two bombs exploded outside a Sunni Muslim mosque in the Iraqi city of Baquba as worshippers left Friday prayers, killing at least 43 people in one of the deadliest attacks in a month-long surge in sectarian violence.
Several other bombings claimed lives around the country - with 19 killed near a commercial complex in the west of Baghdad, as mounting violence intensified fears of a return to all-out civil conflict.
Attacks on Sunni and Shi'ite mosques, security forces and tribal leaders have mounted since troops raided a Sunni protest camp near Kirkuk a month ago.
The increasingly sectarian civil war in neighboring Syria is emboldening Iraqi Sunni insurgents and straining relations between the two Muslim groups in Iraq, where tensions are at their worst since U.S. troops pulled out at the end of 2011.
On Friday, one bomb exploded outside the mosque in Baquba, about 50 km (30 miles) northeast of Baghdad, and a second explosion tore into crowds of people rushing to help victims of the first attack, police said.
Local television showed images of bodies, pools of blood and the victims' scattered shoes.
"I was about 30 meters from the first explosion. When the first exploded, I ran to help them, and the second one went off. I saw bodies flying and I had shrapnel in my neck," said Hashim Munjiz, a college student.
In the Amiriya district of western Baghdad, 19 people were killed by a roadside bomb, police and hospital sources said. Eight others died and more than 20 were wounded by a similar device targeting people gathering for the funeral of a Sunni Muslim cleric who was killed a day earlier.
Two more were killed in the southern outskirts of Baghdad at another funeral for someone who died in one of a series of attacks in the capital on Thursday.
Four others were killed when a roadside bomb exploded next to a coffee shop in the city of Falluja. A roadside bomb in the Doura district of southern Baghdad killed three, according to police and medics.
No group claimed responsibility for the attacks.
Shi'ite Islamist militias, which fought U.S. troops for years after the 2003 invasion, have said they are prepared in case they need to return to war. Sunni insurgents also sometimes hit Sunni targets to provoke conflict.
Sunni Islamist insurgents and al Qaeda's local wing, Islamic State of Iraq, have stepped up attacks since the start of the year to try to provoke a wide-scale sectarian confrontation like that which killed tens of thousands of Iraqis in 2006-2007.
The Sunni militants accuse Prime Minister Nuri al-Maliki's Shi'ite-led government of discriminating against their sect.
The United Nations said leaders from all groups needed to end the violence. "Small children are burned alive in cars. Worshippers are cut down outside their own mosques. This is beyond unacceptable," said U.N. envoy Martin Kobler.
April was Iraq's bloodiest month for almost five years, with 712 people killed, according to U.N. figures.
Since the U.S. withdrawal, Iraq's coalition government has been caught up in a power struggle between majority Shi'ites, minority Sunnis and ethnic Kurds who split cabinet posts between them.
Sunnis, who lost their dominance when the U.S.-led invasion toppled Saddam Hussein, have been protesting for months against Maliki, demanding reforms to tough anti-terrorism laws they say are used to unfairly target their sect.
Iraqi Sunni insurgents, some linked to al Qaeda, say they have formed an alliance with the al-Nusra Front Islamist group fighting against Syrian President Bashar al-Assad.
(Reporting by Kareem Raheem and Raheem Salman in Baghdad and a Reuters reporter in Baquba; Writing by Patrick Markey; Editing by Andrew Heavens and Robin Pomeroy)