Getting your Trinity Audio player ready...

As thousands of Saddam Hussein’s supporters protested in Sunni Arab enclaves across Iraq, the Shiite-led government said it had launched an investigation into the chaotic scene at his execution, which has deepened the nation’s sectarian rift and sparked condemnation around the world.

Iraqi officials said a committee from the Interior Ministry would likely question everyone, including senior Iraqi officials, present at the hanging, where witnesses mocked and jeered the ousted president as he stood at the gallows. Hours later, grainy video of the event, taken with a cell phone camera, was broadcast around the world, bringing more pressure on Iraqi Prime Minister Nouri al-Maliki to take action.

The video triggered outrage, in Iraq and abroad, over Hussein’s undignified and disorderly end. Iraq’s Sunnis declared the execution an act of Shiite revenge. The Vatican, in its official newspaper, called the images from the hanging “a spectacle” that violated human rights and could harm Iraq’s process of reconciliation. The Italian government, which like all members of the European Union opposes the death penalty, said after the appearance of the video that it would push at the United Nations for a worldwide moratorium on capital punishment.

But UN Secretary General Ban Ki Moon, in his first day on the job, stepped back from the UN’s long-standing opposition to the death penalty, saying capital punishment is an issue for each country to decide.

U.S. officials have privately expressed concern at the speed of the execution, which came four days after an appeals court upheld Hussein’s death sentence. Officials said they worked until the final hours to persuade al-Maliki to delay the execution, The New York Times reported. The officials, who spoke on condition of anonymity, said they appealed to al-Maliki not to proceed with the hanging at dawn Saturday because of the onset of a major Islamic festival and because of constitutional and legal questions casting doubt on the legitimacy of the execution.

The investigation of the execution, officials said, would focus on who hurled the taunts and on how the video was leaked, damaging the government’s credibility. Al-Maliki’s political adviser, Sadiq al-Rikabi, said the prime minister was “disappointed about that film.”

“He took the subject very seriously,” al-Rikabi said. “The prime minister tried his best to implement the execution very respectfully.”

In the video, one person yells “Go to hell” at Hussein while another voice is heard chanting “Moqtada, Moqtada, Moqtada,” referring to Moqtada Sadr, the radical Shiite cleric whose father and two brothers were assassinated by Hussein’s regime. The taunts provoked Hussein to hurl insults. Later, images of Hussein’s swinging body were plastered on dozens of Web sites.

The probe could implicate senior Iraqi officials. Munqith al-Faroon, the deputy prosecutor in Hussein’s trial, said Tuesday that he saw two official observers using their cell phones to record Hussein’s last moments. The men, he said, were “recording through their mobiles openly.” He said he did not know them but would recognize them if he saw them again.

Al-Maliki aides said they did not think any officials were behind the video.

“I think [it was] one of the guards, but let us leave everything to the inquiry,” al-Rikabi said.

Al-Faroon countered, “I am confident that they were not the guards, for I checked the guards. I kept them under my eye.”

Al-Faroon, who could be heard in the video appealing for calm, said he had considered walking out during the disorderly moments, which would have halted the execution because his presence was required by law. But the room quieted.

“If there were other violations, I would have stepped out,” he said.

Al-Faroon said he did not how the video cell phones got into the execution room at the former military intelligence headquarters, where Hussein’s government had tortured and killed his opponents. Everyone at the hanging, he said, was searched and their phones were taken. “Even my cell phone, which had no camera, was taken.”