Baghdad, Iraq ? A car bomb aimed at a leading Shiite Muslim politician missed its target Monday but killed at least 10 people, some of them Iraqis simply passing by Abdul-Aziz al-Hakim’s house during the morning rush hour.

“We have chosen nonviolence, and we will stick to it,” al-Hakim told the Reuters news agency after the suicide bomber struck, pledging to keep his Supreme Council for the Islamic Revolution in Iraq on the political path. “If we wanted violence, we would have responded a long time ago.”

Iraq’s shaky march toward national elections suffered another blow, however, when the nation’s most established Sunni Muslim political party announced it was dropping out of national elections scheduled for Jan. 30.

In explaining their withdrawal, Iraqi Islamic Party leaders said the country was not ready for the vote, mostly because of the violence and instability that have hit hardest in predominantly Sunni areas. Sunnis make up a fifth of Iraq’s population.

“We are convinced that the election will not be … honest and will not be held in all parts of Iraq,” party chairman Mohsen Abdul Hamid said. He cited violence and misgivings about the electoral commission. Then he added, “Thirdly, Iraqis don’t understand the elections yet.”

Officials with the interim Iraqi government and the U.S.-led coalition that installed it acknowledge the obstacles, including polls showing that most Iraqis are not sure what offices they will be voting for about a month from now.

But officials in Baghdad and Washington express determination to go ahead with the vote, in which Iraqis are to elect a 275-member National Assembly that would draft a constitution. The Iraqi and American leaders say an election in January is not only the next step legally but also the best way to combat an insurgency that is killing dozens of people a week.

While Sunni religious leaders have called for a boycott of the balloting, Sunni politicians are lobbying for a postponement. They argue that an election that most Sunnis see as unfair would fuel the insurgency, not temper it.

“If 70 percent of registered voters showed up in the north, 80 percent in the south and less than 10 percent in other areas, there will be a lack of balance and it will give a distorted picture of the Iraqi reality,” said Adnan Pachachi, a Sunni elder statesman who heads a small group called the Rally of Independent Democrats. “We believe winning incomplete elections is not considered a real victory.”