American forces used aircraft and helicopters to repel the guerrillas.
The large number of attacks, directed at Iraqi security services, was a clear sign of just how powerful the insurgency in Iraq remains — and could be the start of a new push to torpedo the June 30 transfer of sovereignty to an interim transitional government.
U.S. officials had been warning of this very scenario, reports CBS News Correspondent Kimberly Dozier. The coordinated spate of attacks is intended to show that the coalition and the new Iraqi government cannot provide the one thing Iraqis want most — security.
Iraq's interim prime minister, Iyad Allawi, said the attacks were an attempt to harm the Iraqi people and "to foil the democratic process." He said the situation was under control.
In other developments:
In Baghdad, the Health Ministry said at least 66 people were killed and 268 injured nationwide. However, those figures did not include U.S. dead and injured.
Some of the heaviest fighting was reported in Baqouba, 35 miles northeast of Baghdad, where two American soldiers were killed and seven were wounded, the U.S. 1st Infantry Division said. Attackers also targeted police stations in Ramadi, Mahaweel, and the northern city of Mosul, where car bombs rocked the Iraqi Police Academy, two police stations and the al-Jumhuri hospital.
Khalid Mohammed, an official at the hospital, said dozens of injured were brought there. At least 50 people died and 170 were wounded there, he said. A U.S. soldier also was killed and three were wounded in Mosul. The deaths Thursday brought the U.S. toll in Iraq to about 848 soldiers.
Mosul's governor imposed a 9 p.m.-6 a.m. curfew, and the city television station urged people to stay home for the "general good."
In other attacks, four Iraqi soldiers were killed in an explosion near a checkpoint manned by Iraqi and American soldiers in the southern Baghdad district of Dora. Three U.S. soldiers tended to what appeared to be a wounded American soldier on the road. The soldier's helmet lay nearby. Black smoke and flames shot up from a burning pickup truck.
Also in Baghdad, insurgents attacked four Iraqi police stations using mortars, hand grenades and AK-47s on Wednesday and Thursday. Police fought back and defended the stations with minimal assistance from coalition forces, a U.S. statement said.
A statement quoted Thursday by a Saudi Web site claimed responsibility for the Baqouba attacks in the name of Abu Musab al-Zarqawi, who said the insurgents belong to his Tawhid and Jihad movement. He called residents to "comply with the instructions of resistance."
U.S. aircraft dropped three 500-pound bombs against an insurgent position near the city soccer stadium in Baqouba, said Maj. Neal E. O'Brien, a U.S. 1st Infantry Division spokesman. Insurgents roamed the city with rocket launchers and automatic weapons and occupied two police stations.
Insurgents destroyed the home of the police chief of the Diyala province where Baqouba is, O'Brien said.
At the main hospital in Baqouba, doctors continuously received injured people and the corridors were spattered with blood. Civilian cars sped up carrying people with gunshot and shrapnel wounds.
U.S. officials projected calm.
"Coalition forces feel confident with the situation," said Brig. Gen. Mark Kimmitt, coalition deputy operations chief.
Explosions and shelling shook Fallujah, 40 miles west of Baghdad, as armed men ran through the streets, witnesses said. Residents said U.S. forces were shelling from positions outside the city and helicopters were in the skies, but the U.S. military could not immediately be reached for comment.
One Marine helicopter made an emergency landing, but no one was wounded.
U.S. forces manning a checkpoint opened fire on a local government convoy that included Fallujah's mayor and police chief, who were trying to meet the Americans to discuss the violence, an Iraqi police lieutenant said on condition of anonymity. The convoy turned back, and no injuries were reported.
A motorist who drove through Fallujah on Thursday morning said Iraqi police and insurgents were cooperating, chatting amicably along the streets, and seemed to be working together.
U.S. forces launched two airstrikes on Fallujah in recent days against what they said were safehouses of al-Zarqawi, whose group claimed responsibility for the beheading of American hostageand South Korean hostage , whose decapitated body was found Tuesday between Baghdad and Fallujah.
In other attacks on security forces, insurgents wearing black and using masks fired rocket-propelled grenades to attack two police stations in the insurgent stronghold of Ramadi 60 miles west of Baghdad, police said.
Seven people were killed and 13 were wounded, hospital officials said.
Another group attacked the Farook police station in Ramadi, also with rocket-propelled grenades, Sami said. In a third assault, insurgents attacked a Ramadi government building, destroying several police cars.
And in Mahaweel, a bomb exploded outside the police station, killing one officer and wounding six in the town 40 miles from Baghdad.