BAGHDAD (AFP) -- A string of bomb attacks in Iraq killed at least 25 people and wounded dozens of others, as U.S. and Iraqi officials defended the building of a wall around a Sunni enclave in Baghdad.

A car bomb near an office of Kurdish leader Massud Barzani's Kurdish Democratic Party killed 10 people and wounded 20 more in Tal Isquf, a mainly Christian village in northern Iraq, party spokesman Abdul Gani Ali said.

Witnesses said some of the victims were thought to be Kurdish "peshmerga" fighters.

Bomb attacks also ravaged Baghdad, the epicenter of a campaign by Al-Qaeda militants to undermine Iraq's Shiite-led government and to foment sectarian violence between Sunnis and Shiites.

A suicide bomber blew himself up outside a restaurant near the capital's fortified Green Zone, killing seven people and wounding 14, a security official said.

The walled zone houses the U.S. embassy and the Iraqi parliament, where a suicide bomber struck on April 12, killing one lawmaker.

Two more car bombs exploded in a parking lot near the Green Zone, opposite the Iranian embassy and close to the Iraqi defense ministry. A bystander was wounded in the first blast.

The embassy was not damaged in either explosion and it was unclear if it was targeted.

North of Baghdad in the violence-plagued city of Baquba, a bomber exploded his car near the city council building, killing four policemen, police Lieutenant Ahmed Ali said.

In the western city of Ramadi, a car bomb destroyed a restaurant, killing four customers, said senior provincial security official Colonel Tareq al-Dulaimi.

It was not clear whether the restaurant was attacked by a suicide bomber, but an insurgent did kill himself in a similar assault on a nearby police checkpoint that wounded four officers and a bystander, he told AFP.

"I cannot confirm the attack on the restaurant was a suicide attack, there are many body parts. There are 20 people wounded, some of them seriously," said Dulaimi, who works with a coalition of tribes opposed to Al-Qaeda.

A spokesman for the U.S. Marines in Ramadi, Lieutenant Roger Hollenbeck, told AFP that both attacks were launched by suicide car bombers.

Iraqi and U.S. forces are battling an anti-American insurgency in Ramadi four years after the March 2003 invasion of Iraq, but in recent months an alliance of Sunni tribes dubbed the Anbar Awakening has risen up to help them.

An American soldier was killed by a bomb near his base at Muqdadiyah 100 kilometres (60 miles) north of Baghdad on Monday, taking to 61 the number of U.S. fatalities this month, the U.S. military said.

His death brought to 3,321 the American military's losses in Iraq since the invasion, according to an AFP count based on Pentagon figures.

A British soldier was also killed in the southern city of Basra, the ministry of defense said in London, taking to 145 the number of British troops who have died in Iraq since 2003.

Iraqi and U.S. officials, meanwhile, defended their decision to construct a three-mile (five kilometre) wall around Baghdad's dangerous Sunni district of Adhamiyah, even though Prime Minister Nuri al-Maliki opposed it.