The military said Tuesday that three American soldiers were killed and eight wounded in separate attacks in Iraq in the past 24 hours.

Further highlighting the chaotic situation, electricity was knocked out across the country when saboteurs blew up an oil pipeline junction in northern Iraq, sparking a fire that set off a chain reaction in power generation systems.

In Cairo, the head of the Arab League warned that "the gates of hell are open in Iraq and the situation is getting more complicated and tense." Amr Moussa appealed to Arab countries "to help Iraq to overcome this crisis."

Despite the violence, U.S. and Iraqi forces claimed two successes in recent days. U.S. troops on Tuesday ended their siege of the northwest city of Tal Afar, saying they had cleared it of militants after 12 days of fighting that killed dozens of people.

And on Thursday, U.S. troops entered Samarra, north of Baghdad, for the first time since May 30 after negotiating a deal with local leaders. The city had been a stronghold of Sunni insurgents.

U.S. commanders insisted attacks like Tuesday's won't deter Iraqis from joining the police and Iraqi national guard to help end the violence.

"I'm pretty sure that it's not driving them away, it may in fact have the opposite reaction and strengthen their resolve to join the Iraqi forces," said Lt. Col. Steven Boylan, spokesman for coalition forces in Iraq. "They are tired of the killings and the bombings."

Crowds at the scene of the Baghdad explosion pumped their fists in the air and directed their anger against the United States and Allawi for failing to protect the station even though police recruiting points have repeatedly been attacked.

"Bush is a dog," they chanted.

"Such places were targeted before," said Ali Abul-Amir, who had been waiting to join the police force. "I blame Ayad Allawi's government for what happened because they did not take the necessary security measures."

With medical teams overwhelmed, residents covered burned bodies with blankets and lay them on stretchers. Others collected severed hands, arms and legs and put them into cardboard boxes.

"Seconds earlier, people were drinking tea or eating sandwiches and then I could see their remains hanging from trees," said Mahdi Mohammed, who was outside his barber shop when the explosion went off. "I could see burning people running in all directions."

Some directed their anger at the militants.

"Such acts cannot be considered part of the resistance (against American forces). This is not a jihad, they are not mujahedeen," said Amir Abdel Hassan, a teacher. "Iraq is not a country, it's a big graveyard," he said.