A bomb attached to a pickup truck in an Iraqi Shiite lawmaker's convoy wounded five people, including three of his bodyguards, when it exploded in the Iraqi capital Monday, officials said.

A police official at the scene told The Associated Press that the legislator, Izzat al-Shabander, was not in the convoy when it was targeted. He said the two other people wounded in the blast were bystanders.

Pools of blood could be seen on the ground next to the burnt-out pickup truck on the scene.

The official spoke on condition of anonymity because he was not authorized to speak to the press.

Although overall violence has decreased in Iraq over the past two years, bombings remain a daily occurrence. Massive bombings also continue to take place, killing scores. Many analysts say they expect a surge in violence in the run-up to parliamentary elections scheduled for March 7.

Attacks on Iraqi politicians have been common since the 2003 overthrow of Saddam Hussein's regime. Roadside bombs, drive-by shootings and ambushes have been the most commonly used methods to kill politicians, senior law enforcement officers, government officials and judges.

Also on Monday, Iraqi officials announced they will soon begin new excavations based on reports of a new mass grave, near the holy city of Karbala south of Baghdad.

Dr. Kamil Ameer Hashim, a spokesman for the ministry of human rights, said that the suspected grave site had not yet been opened and it was unclear how many people might be inside. Officials had decided on the location based on interviews with the families of the dead, he said.

Meanwhile, the remains of more than 70 people, including women, children and the elderly, have been excavated from a different mass grave in Topzawa near the city of Kirkuk in northern Iraq, he said. Officials began digging there two months ago but have not yet finished their work.

No one knows how many victims of Saddam's regime lie in mass graves around Iraq. Tens of thousands of Kurds were killed or expelled from Iraq in the late 1980s and then again during the Kurdish uprising that followed the first Gulf War in 1991. Many political prisoners were also killed and secretly buried.