BEIRUT - The U.N. humanitarian chief toured the shattered Syrian district of Baba Amr on Wednesday but found most residents had fled following a bloody military siege, while activists accused the government of trying to cover up evidence of atrocities there.
The visit by Valerie Amos, the New York-based undersecretary-general for humanitarian affairs, was the first by an independent outside observer since the Syrian military began its month-long assault of the rebellious neighbourhood. A key stronghold of the uprising to oust authoritarian President Bashar Assad, it was wrested from rebel control on March 1.
Amos made no statement, but a spokesman for the International Committee of the Red Cross said she entered the ravaged neighbourhood with a team from the Syrian Red Crescent that had been waiting nearly a week to be allowed in to deliver aid.
"The Syrian Arab Red Crescent stayed about 45 minutes inside the neighbourhood," Red Cross spokesman Hicham Hassan said in Geneva. "Volunteers say that most inhabitants have fled Baba Amr."
The Syrian regime has kept the neighbourhood sealed off over the past six days, saying it was too dangerous for humanitarian workers to enter. But activists accused the government of engaging in a "mopping-up" operation to hide their atrocities.
"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."
Secretary of State Hillary Clinton lashed out at the delays.
"The regime's refusal to allow humanitarian workers to help feed the hungry, tend to the injured, bury the dead, marks a new low," she said. "Tons of food and medicine are standing by while more civilians die and the regime launches new assaults."
Amos said the aim of her two-day visit to Syria was "to urge all sides to allow unhindered access for humanitarian relief workers so they can evacuate the wounded and deliver essential supplies."
She met with Syria's foreign minister on Wednesday and was to meet other government officials in Damascus on Thursday, but it was unclear whether she would be allowed to return to Baba Amr or whether any aid deliveries were imminent.
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, U.S. Defence Secretary Leon Panetta delivered a sober assessment of Syria's sophisticated air defences and its extensive stockpile of chemical weapons -- a strategic reality check to demands for U.S. military action to end Assad's deadly crackdown on his people.
Republican Sen. John McCain has called on the Obama administration to launch U.S. airstrikes to end Assad's crackdown, but Panetta pushed back Wednesday against the demand.
"What doesn't make sense is to take unilateral action right now," Panetta told the Senate Armed Services Committee. "I've got to make very sure we know what the mission is. ... Achieving that mission at what price?"
Panetta and Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, described a well-armed Syria that bears little resemblance to what the U.S. military and its allies faced in Libya. Syria's air defences are five times more sophisticated than Libya's, and its chemical and biological weapons stockpile is 100 times larger, they said.
Suppressing the air defences would require a sustained air campaign over an extended period of time with a significant number of aircraft, and the U.S. would have to lead the effort, Dempsey said.
Because the air defences are located in populous neighbourhoods, airstrikes could mean scores of unintended deaths, Panetta said.
Dempsey warned of the "need to be alert to extremists," and other hostile actors, including Iran, which he said "has been exploiting the situation and expanding its support to the regime."
"And we need to be especially alert to the fate of Syria's chemical and biological weapons. They need to stay exactly where they are," Dempsey said.
After seizing Baba Amr from the rebels, regime forces now appear to be turning their attention to other rebellious areas. A wave of new arrests was reported in Homs by the Local Coordinating Committees, an activist group, as well as assaults on the northern province of Idlib near Turkey.
The shift suggests 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. There also were reports of snipers in Homs province.
Russia and China, powerful Syrian allies that have blocked a Security Council resolution against Syria, have made clear they are still standing by the regime in Damascus.
Still, in a sign of China's growing alarm, Chinese Commerce Minister Chen Deming said Beijing was pulling its workers out of Syria because of the violence.
"I can tell you most Chinese workers have been withdrawn from that country to China," he told a news conference. "There are only about 100 people left there taking care of projects, assets and property. We will wait until the local situation stabilizes."
In Moscow, Russian leader Vladimir Putin said the government wasn't considering granting political asylum to Assad, shooting down rumours that such an offer is on the table as a way to end the Syrian regime's deadly crackdown.
Putin, who is currently prime minister but regained the presidency in an election Sunday, said "We aren't even discussing the issue" of granting asylum to Assad.
