After a U.S. troop withdrawal some criticized as premature, could Iraq experience the kind of instability and violence seen in South Vietnam in 1973? Or is this a last, desperate show of strength from a fading Al-Qaeda?

BAGHDAD (AP) — A wave of at least 14 bombings ripped across Baghdad Thursday morning, killing at least 60 people in the worst violence in Iraq for months. The apparently coordinated attacks struck days after the last American forces left the country and in the midst of a major government crisis between Shiite and Sunni politicians that has sent sectarian tensions soaring.

The bombings may be linked more to the U.S. withdrawal than the political crisis, but all together, the developments heighten fears of a new round of Shiite-Sunni sectarian bloodshed like the one a few years back that pushed Iraq to the brink of civil war.

There was no immediate claim of responsibility. But the bombings bore all the hallmarks of al-Qaida’s Sunni insurgents. Most appeared to hit Shiite neighborhoods, although some Sunni areas were also targeted. In all, 11 neighborhoods were hit by either car bombs, roadside blasts or sticky bombs attached to cars. There was at least one suicide bombing and the blasts went off over several hours.

Coordinated campaigns such as this generally take weeks to plan, and could have been timed to coincide with the end of the American military presence in Iraq, possibly to undercut U.S. claims that they are leaving behind a stable and safe Iraq. Al-Qaida has long sought to sow chaos and provoke the type of Shiite militant counterattacks that defined Iraq’s insurgency.

The deadliest attack was in the Karrada neighborhood, where a suicide bomber driving an explosives-laden vehicle blew himself up outside the office of a government agency fighting corruption. Two police officers at the scene said the bomber was driving an ambulance and told guards that he needed to get to a nearby hospital. After the guards let him through, he drove to the building where he blew himself up, the officers said.

Sirens wailed as ambulances rushed to the scene and a large plume of smoke rose over the area. The blast left a crater about five yards (meters) wide in front of the five-story building, which was singed and blackened.

“I was sleeping in my bed when the explosion happened, said 12-year-old Hussain Abbas, who was standing nearby in his pajamas. “I jumped from my bed and rushed to my mom’s lap. I told her I did not to go to school today. I’m terrified.”

At least 25 people were killed and 62 injured in that attack, officials said. They spoke on condition of anonymity because they were not authorized to speak to the media.

Figures gathered from Iraqi health and police officials across the city put the death toll at 60, and 160 injured. The spokesman for the Iraqi health ministry put the death toll at 57 and said at least 176 people were injured. But conflicting casualty figures are common in the aftermath of such widespread bombings.

For many Iraqis and the Americans who fought a nearly nine-year war in hopes of leaving behind a free and democratic country, the events of the past few days are beginning to look like the country’s nightmare scenario. The fragile alliance of Sunnis and Shiites in the government is completely collapsing, large-scale violence with a high casualty toll has returned to the capital, and Prime Minister Nouri al-Maliki is displaying an authoritarian streak and may be moving to grab the already limited power of the Sunnis.

Al-Maliki’s Shiite-led government this week accused Vice President Tariq al-Hashemi, the country’s top Sunni political leader, of running a hit squad that targeted government officials five years ago, during the height of sectarian warfare. Authorities put out a warrant for his arrest.

Many Sunnis fear this is part of a wider campaign to go after Sunni political figures in general and shore up Shiite control across the country at a critical time when all American troops have left Iraq.

Because such a large-scale, coordinated attack likely took weeks to plan, and the political crisis erupted only few days ago, the violence was not likely a direct response to the tensions within the government. Also, al-Qaida opposed Sunni cooperation in the Shiite-dominated government in the first place and is not aligned with Sunni politicians so does not feel any responsibility to press for any Sunni role in Iraq’s power structure.

The Sunni extremist group often attacks Shiites, who they believe are not true Muslims.

U.S. military officials worried about a resurgence of al-Qaida after their departure. The last American troops left Iraq at dawn Sunday.

Al-Qaida in Iraq is severely debilitated from its previous strength in the early years of the war, but it still has the capability to launch coordinated and deadly assaults from time to time.

The attacks ratchet up tensions at a time when many Iraqis are already deeply worried about security. The real test of whether sectarian warfare returns, however, will be whether Shiite militants are resurgent and return to the type of tit-for-tat attacks seen at the height of sectarian warfare in 2006-2007.

During that fighting, neighborhoods that used to contain a mixture of Shiites and Sunnis were purged entirely of one Muslim sect or another. Neighbors turned on neighbors in Baghdad, and the result today is city where neighborhoods are much less religiously mixed and sectarian lines are clearly drawn.

Iraqis are already used to horrific levels of violence, but many wondered when they would be able to enjoy some measure of security and stability after years of chaos.

“My baby was sleeping in her bed. Shards of glass have fallen on our heads. Her father hugged her and carried her. She is now scared in the next room,” said one woman in western Baghdad who identified herself as Um Hanin. “All countries are stable. Why don’t we have security and stability?”

While Baghdad and Iraq have gotten much safer over the years, explosions like Thursday’s are still commonplace.

Al-Maliki’s tactics are another source of concern, especially for Sunnis. He is also pushing for a vote of no-confidence against another Sunni politician, the deputy prime minister Saleh al-Mutlaq.

Ayad Allawi, who heads a Sunni-backed party called Iraqiya, laid the blame for Thursday’s violence with the government. The Iraqiya coalition also includes al-Hashemi and al-Mutlaq, and Allawi has been one of al-Maliki’s strongest critics. Allawi warned that violence would continue as long as people are left out of the political process.

“We have warned long ago that terrorism will continue … against the Iraqi people unless the political landscape is corrected and the political process is corrected, and it becomes an inclusive political process and full blown non-sectarian institutions will be built in Iraq,” Allawi told The Associated Press, speaking from neighboring Beirut.

Associated Press writers Rebecca Santana and Sinan Salaheddin contributed to this report.