Militants blew up 13 cars in three hours, wounding at least 20 people, while 13 Iraqis were killed in other violence yesterday and on Sunday.
Yesterday's worst bloodshed came in eastern Baghdad, where police said gunmen killed five people at a butcher shop and a bomb killed two police officers at a gas station.
Two more Iraqis were slain and five wounded by gunfire at a Sunni mosque in southern Baghdad, while a Shiite sheik was fatally shot at a market in the same part of the city.
In the northern city of Mosul, about a dozen gunmen attacked a police checkpoint, killing a bystander and wounding three policemen, police said.
Eight of the cars bombs exploded in Baghdad and wounded a total of 11 people, police said. Officers later destroyed a ninth car bomb that failed to go off.
A suicide car bomber near Tikrit injured six civilians, and in the northern city of Kirkuk, a bomb aimed at an Iraqi police convoy wounded three civilians, police said. Other car bombings in Kirkuk and in Muqdadiyah caused no injuries.
A gasoline shortage because of insurgents' threats against tanker-truck drivers has added to the unease. Police killed two protesters in oil-rich Kirkuk on Sunday when a demonstration by 500 people over rising fuel prices escalated into a riot. Authorities imposed a curfew on the city.
Elsewhere, Sunni Arabs made their opening bid on Sunday in what could be protracted negotiations to form a new government. Leaders of the minority's main political group, the Iraqi Accordance Front, traveled to the northern city of Irbil for a meeting yesterday with the president of the Kurdish region.
The Kurdish region in Iraq's north already has seen a flurry of postelection bargaining between Kurds and the governing Shiite Muslim religious party, the United Iraqi Alliance.
Preliminary results from the Dec. 15 election gave the Shiite group a strong lead in the voting for Iraq's 275-member parliament, but not enough for it to govern without other political blocs.
A year ago, it took nearly three months of negotiations between the Shiite religious alliance and a coalition of Kurdish parties to form an interim government after a Jan. 30 election that was boycotted by the Sunni Arabs at the core of the insurgency.
Early 2006 looks more crucial as Iraq tries to shape an administration that will govern for four years. US officials are pushing the parties to form a broad-based coalition government.
"This is perceived, inappropriately or inaccurately perhaps, by the enemy as a time of vulnerability, as the government transitions from its transitional government to a permanent government, to the constitutional-based, democratically elected four-year permanent government," said Brigadier General Donald Alston, spokesman for the US-led coalition force.