BAGHDAD - A series of bombings struck Baghdad and a neighboring province Monday, killing at least 10 people and wounding 40, including a deputy oil minister who was injured when a bomb went off in front of his house as he was leaving for work.

Most of the six blasts occurred in Baghdad, reinforcing U.S. military warnings that extremists remain capable of launching attacks in the capital despite an overall improvement in security.

The attacks took place on the eve of the U.S. presidential election between Sen. Barack Obama and Sen. John McCain, who hold widely differing views on the war in Iraq.

Six people died when a pair of bombs -- one of them hidden in a trash can -- exploded in Tahariyat square in the Karradah district of central Baghdad during the morning rush hour.

Police said 21 people were wounded, including 10 policemen and two women. The blasts blew out store fronts lining the square in a mostly Shiite area of eastern Baghdad.

Soon afterward, a bomb went off in front of the north Baghdad home of Abdul-Sahib Salman Qutub, a deputy oil minister in charge of crude oil production. Ministry spokesman Assem Jihad said the bomb was attached to Qutub's car and went off as he was walking to the vehicle.

Qutub was treated and released from a hospital, but his driver was seriously injured, Jihad said.

One policeman was killed and six were injured in a roadside bombing in east Baghdad, police said. Another policeman and a civilian were wounded when a bomb went off near a police patrol in the western part of the capital.

In Baqouba, about 55 kilometres northeast of Baghdad, a car bomb blew up across the street from the provincial council headquarters, killing two policemen and a 10-year-old girl, Diyala provincial police said. Nine people were wounded.

A group of people were inside the council headquarters attending a conference on how to protect journalists in Diyala, one of Iraq's most unstable provinces. None of the participants was hurt, police said.

The police officials all spoke on condition of anonymity because they were not supposed to release the information.

U.S. officials say attacks in Baghdad are averaging about four a day, down nearly 90 per cent from levels of late 2006 when Shiite-Sunni fighting was at its high point and just before the U.S. troop surge, which helped bring down violence in the capital.

Nevertheless, Monday's bombings show that extremists retain the capability to stage bombings even in the heart of the heavily guarded Iraqi capital.

Last week, unknown assailants blew up a major water pipeline in northern Baghdad, interrupting water supplies to thousands of people before the damage was repaired.

U.S. military commanders have warned that both Sunni and Shiite extremists remain active and have cautioned against major reductions in the 145,000-strong U.S. force until Iraqi police and soldiers are capable of maintaining security.

But U.S. strategy in Iraq may change depending on the outcome of Tuesday's presidential contest.

Obama opposed the Iraq invasion of 2003 and has called for a complete withdrawal of combat troops in 16 months. McCain supported the decision to go to war and opposes scheduling a troop withdrawal, saying the U.S. strategy since the 2007 troop surge is succeeding.

The U.S. and Iraq are negotiating a new security agreement which would end the U.S. military presence by 2012 and give Iraqis a greater role in managing combat operations.

Prime Minister Nouri al-Maliki's government is waiting for a U.S. response to proposed changes in the draft agreement before referring it to parliament for a final decision. The agreement must be approved by the end of the year when the UN mandate governing coalition operations expires.

Without an agreement or a new mandate, U.S. military operations would cease on Jan. 1.

The U.S. contends that lasting peace will not come to Iraq until the rival religious and ethnic groups reach power-sharing agreements. As part of that process, Iraq's parliament approved a bill granting Christians and other small religious groups seats on several provincial councils.

The measure was the last legislative hurdle standing in the way of provincial elections by the end of January. Christians complained, however, that the bill granted them too few seats.

Iraqi Christians, believed to number no more than 3 percent of Iraq's 27 million people, have complained of violence, intimidation and the loss of status since the rise of Islamic militancy in the wake of the U.S. invasion.

On Monday, however, al-Maliki, a Shiite, pledged to protect the Christians, whom he described as "an essential component" of Iraqi society.