Today, gunmen killed Baghdad Governor Ali Radi al-Haydari.
At the same time, a suicide car bomber killed 10 people near the Green Zone -- the capital's heavily fortified "safe area" for U.S. and Iraqi officials.
The attacks followed a suicide car bombing in Baghdad yesterday just outside the party headquarters of interim Prime Minister Iyad Allawi. Allawi was elsewhere, but the attack killed two people just as his party was poised to announce its candidates for the elections on 30 January.
Analysts say the insurgents are escalating their attacks to persuade voters to stay home. The attacks -- including the mortar shelling of two voter registration centers on 2 January -- seek to show that the government cannot assure the security of its supporters or even of its own members.
Mahmud Uthman, a member of the former Iraqi Governing Council, told RFE/RL from London that the insurgents view the election as a "showdown" with Iraq's U.S.-supported administration.
"They are escalating their operations just as we are going toward the election because the election now, in our country, has become [the occasion for] a sort of defiance," Uthman said. "[U.S. President George W.] Mr. Bush says it should be on the 30th [of January] and the insurgents say it shouldn't be done."
U.S. and Iraqi officials hope that 30 January will see large numbers of Iraqis turn out to vote for a new National Assembly that will choose the next interim government.
A big turnout would give the new government a strong popular mandate. Washington hopes that mandate could help it finally crush the insurgency and begin reconstruction. The insurgents see minimizing voter turnout as the best way to undermine those plans.
Iraqi President Ghazi Ajil al-Yawir said today that security concerns raise the question of whether the elections should be postponed.
"There will be some kind of conflict of interest if we [the Iraqi government] say, 'Let's postpone [the election],' or, 'Let's go [forward].' But the United Nations and the independent electoral committee are probably the two parties who can have the final say."
The insurgents' successful operations come despite determined efforts by U.S. forces in December to weaken them through attacks on their bases in Al-Fallujah and some other towns in Sunni-populated central Iraq.
U.S. military officials had hoped that establishing government control in Al-Fallujah would deal not only a military but also a psychological blow to the insurgency by demonstrating Baghdad's determination to assure all areas of Iraq can participate in the poll.
But despite heavy losses, the insurgents have rebounded quickly.
As the fighting in Al-Fallujah came to a close, insurgents took over police stations in the northern city of Mosul, setting them ablaze, stealing weapons, and roaming the streets at will. Their show of strength ended only when U.S. forces rushed in reinforcements.
As the insurgents step up attacks, they are making increasing use of suicide bombings. The bombers are proving particularly effective in infiltrating areas where gunmen might quickly be detected.
On 2 January, two suicide bombers in a car packed with explosives hit a bus full of members of Iraq's paramilitary National Guard just outside a U.S. military base near Balad, north of Baghdad. The blast killed 23 guardsmen.
One bomber was even able to penetrate a heavily protected U.S. military base in Mosul in late December. The explosion killed 18 U.S. soldiers and three Iraqi National Guardsmen.
Jeremy Redmon, a journalist for the U.S. "Richmond Times-Dispatch" newspaper, was present during the attack at the U.S. base.
"A huge explosion rocked the whole building," Redmon recalled. "I looked up and about 50 [meters] from me, there was a gigantic fireball in the ceiling of this tent. It is really just a cavernous tent. There were hundreds of soldiers in there having lunch at the time."
Counterinsurgency experts said such attacks require not only careful planning but highly accurate information about the targets themselves. The ability of insurgents to gather such intelligence is widely attributed to their infiltration of organizations such as the National Guard and ruling political parties.
The insurgent groups are reported to include supporters of the former regime, self-declared Iraqi nationalists, and Islamist extremists. It is unclear to what extent the groups work together toward their common goal of driving U.S. troops from Iraq and preventing the creation of a new political order.
At least one extremist Sunni group has shown itself ready to fan Iraq's communal tensions by also directly attacking the Shi'a community. The group, led by self-declared Al-Qaeda ally Abu Mus'ab al-Zarqawi, tried to assassinate the leader of the best organized Shi'a political party in a suicide bombing in Baghdad in December.
The attack on Abd al-Aziz al-Hakim, leader of the Supreme Council for the Islamic Revolution in Iraq (SCIRI), suggested that insurgents could seek to gain popular Sunni support by portraying themselves as defending the community's interests against those of the Shi'a.
The attack came as some Sunni leaders urged their communities to boycott the polls over fears they could hand power to the Shi'a majority.
In an effort to calm tensions after the attack, al-Hakim said he would not respond with force. He heads a candidate list expected to win the most votes among the Shi'a, who make up 60 percent of Iraq's population.