A bomb was placed in a parked car which exploded in the marketplace of Khalis, killing 10 people [Reuters]

Two separate attacks have killed 18 people in Diyala province in northeastern Iraq, officials say.

Both attacks - a marketplace bombing and an assault on the home of an anti-al-Qaeda leader - took place on Thursday morning.

A bomb placed in a parked car exploded in the town of Khalis as morning shoppers were starting to arrive, killing 10 people and wounding 22 others, police officials said.

Khalis, a Shia enclave 80km north of Baghdad, is located in the largely Sunni province of Diyala. The province was a hotbed of al-Qaeda in Iraq during the height of the country's violence in 2004-2007.

Elsewhere in Diyala, assailants stormed the home of the anti-al-Qaeda leader at dawn and killed eight people, police said.

The victims of the attack in the town of Buhriz, about 60km north of Baghdad, included the local leader of the pro-government Sahwa, or Awakening Councils movement, and six members of his family, four of whom were women.

Faris al-Azawi, the spokesman of Diyala's health directorate, confirmed the death tolls in both Khalis and Buhriz.

The attacks came as US Vice-president Joe Biden met Iraqi officials on a trip designed to chart a new relationship between the two countries ahead of the withdrawal of US forces by the end of this year.

Iraqi security officials maintain that they are fully prepared for the American withdrawal, which is required under a 2008 security pact between the US and Iraq. About 13,000 US troops are still in the country, down from a one-time high of about 170,000.

At least 56 Iraqis have been killed in separate attacks across the country in the past eight days.