BEIRUT (AP) -- The U.N. humanitarian chief got the first look inside the shattered district of Baba Amr on Wednesday but found most people already had fled the rebellious neighborhood in Homs following a devastating military siege.
Activists have accused the government of sealing off Baba Amr for nearly a week while it tried to cover up evidence of atrocities over the past month.
The Geneva-based U.N. humanitarian chief Valerie Amos arrived in Damascus earlier in the day, then headed straight to the Baba Amr, which the military wrested from rebel control last Thursday after a battle that lasted nearly four weeks. Homs is one of the strongholds of Syria's year-old uprising to oust authoritarian President Bashar Assad.
"The Syrian Arab Red Crescent stayed about 45 minutes inside the neighborhood," ICRC spokesman Hicham Hassan said in Geneva. "Volunteers say that most inhabitants have left Baba Amr to areas that have already been visited last week by the Red Crescent and the ICRC."
The siege of Baba Arm outraged the international community, and the U.S. said Assad was acting like a war criminal. One powerful U.S. senator, John McCain, is advocating U.S. airstrikes to end Assad's crackdown on the opposition. But Defense Secretary Leon Panetta pushed back against the demands.
"What doesn't make sense is to take unilateral action right now," Panetta told the Senate Armed Services Committee about advising President Barack Obama to dispatch U.S. forces. "I've got to make very sure we know what the mission is ... achieving that mission at what price."
The government has kept Baba Amr sealed off over the past six days, saying it was too dangerous for humanitarian workers to enter. But activists say the government has been engaged in a "mopping-up" operation to hide their activities.
"They haven't let anyone in for a week, and now they are going to let them in?" Homs activists Tarek Badrakhan told The Associated Press. "Today it's simple: They finished their crimes and hid all the proof. Now they think they can show that everything is normal."
Khaled Erq Sousi, head of the emergency committee of the Syrian Red Crescent, confirmed that Amos was on the trip.
Amos has said the aim of her visit is "to urge all sides to allow unhindered access for humanitarian relief workers so they can evacuate the wounded and deliver essential supplies."
The U.N. says more than 7,500 people have been killed since Syria's uprising began. Activists put the death toll at more than 8,000.
In Washington, Senator McCain, the top Republican on the Senate Armed Services Committee, said the estimated 7,500 dead in the Syrian uprising calls for U.S. leadership that a Democratic president, Bill Clinton, displayed during the Bosnian war in the 1990s and that Obama eventually showed on Libya last year.
"In past situations, America has led. We're not leading, Mr. Secretary," McCain told Panetta.
The Pentagon chief later added that the United States is not holding back and is leading in Iraq, Afghanistan, Syria and the war on terrorism.
Testifying before the committee, Army Gen. Martin Dempsey and Panetta offered a cautionary note to the call by McCain to launch U.S. airstrikes against Assad's regime.
"This terrible situation has no simple answers," Panetta told the panel.
After seizing Baba Amr from the rebels, regime forces appeared to be turning their attention to other rebellious areas, including the northern province of Idlib near Turkey. The shift suggested that the Syrian military is unable to launch large operations simultaneously, even though the security services remain largely strong and loyal.
According to witnesses, Syrian troops shelled the northern villages in Idlib on Wednesday.
AP writers Ben Hubbard in Beirut, Frank Jordans and John Heilprin in Geneva, Albert Aji in Damascus, Syria, Donna Cassata in Washington and Nebi Qena in Yayladagi, Turkey, contributed to this report.