A SPATE of violence across Iraq has killed at least 10 people, as officials said repairs to government offices struck by massive bombings last week will cost about $US16 million ($17.5 million).

A UN special envoy, meanwhile, arrived in Baghdad to make a preliminary report on security in the Iraqi capital after the massive blasts and similar attacks in August killed 250 people.

In last night's deadliest attack, five people were killed and 37 wounded when a bomb hidden in a cooler on the back of a bicycle exploded in the Shi'ite city of Mussayib in Babil province.

Police said the bicycle had been left at the market in Mussayib, 60km south of Baghdad.

The western city of Ramadi, capital of the predominantly Sunni province of Al-Anbar, a former rebel stronghold, was targeted by two suicide bombings, police said.

One of the attackers detonated a car bomb at the city's western entrance, killing two people and wounding four others, according to Colonel Jabbar Ajaj.

Col Ajaj added that another suicide attacker blew himself up near a police station outside Ramadi, 100km from Baghdad, but killed only himself. No one was wounded.

In the Shi'ite holy city of Karbala, 110km south of the capital, a magnetic bomb affixed to a bus went off as the vehicle was approaching a security checkpoint, killing a woman.

The "sticky bomb" attack also wounded 12 people, including five women, medical and security officials said.

Meanwhile, a government employee and a lawyer were shot dead and two civilians were wounded in attacks in the restive northern city of Mosul.

Ayseh Mohsen al-Hobaidi, a respected lawyer, was shot dead by gunmen in his office in central Mosul about 7.30pm local time, police said.

It was not immediately clear why the father-of-three in his 50s was targeted, as police said he had no known political background.

The civil servant, meanwhile, was shot dead by gunmen as he was driving his car in the west of the city, 350km from the capital, a police officer said.

The officer added that a car bomb targeting an army patrol in western Mosul wounded two people.

In Baghdad, meanwhile, authorities allocated about $US16 million ($17.5 million) to rebuild the ministries of justice and public works and the Baghdad provincial government building, all badly damaged in the October 25 huge blasts.

More than 150 people were killed that day in near-simultaneous vehicle suicide attacks targeting the government buildings at busy Baghdad intersections, in Iraq's deadliest day of violence in more than two years.

The decision to repair the government buildings was taken at a cabinet meeting, during which ministers allocated 16 billion dinars ($14.95 million) for the justice and public works ministries.

Baghdad Governor Salah Abdul Razzaq said the provincial government had earmarked 3 billion dinars ($2.84 million) to repair its offices.

Amid lobbying by Iraq for an independent probe into the attacks in central Baghdad, UN Assistant Secretary General Oscar Fernandez-Taranco is to meet with Iraqi officials today, said Said Arikat, the spokesman for the UN mission.

A UN official, speaking on condition of anonymity, said Mr Fernandez-Taranco would meet cabinet ministers and foreign ministry officials.