BEIRUT (AP) -- The Syrian government on Friday opened a new corridor for rebels and civilians who want to leave the besieged eastern neighborhoods of Aleppo, but the U.N. said planned medical evacuations haven't begun as planned because of a lack of security assurances from the warring sides.
The evacuations, part of a Russia-announced pause in fighting, were announced a day earlier with great hopes by U.N. officials.
But the spokesman for the U.N's humanitarian aid agency, Jens Laerke, described an "astronomically difficult situation," although he declined to specify who was responsible for the breakdown in the plans on Friday.
Speaking to reporters in Geneva, Laerke said that the evacuations couldn't begin "because the necessary conditions were not in place to ensure safe, secure and voluntary" movement of people.
A U.N. official, however, told The Associated Press that Syrian opposition fighters were blocking medical evacuations because the government and Russia were impeding deliveries of medical and humanitarian supplies into the city.
The official, who spoke on condition of anonymity because the United Nations was expected to make an official statement about the hold-up in medical evacuations later on Friday, said intense efforts were under way in Damascus, Aleppo, Geneva and Gaziantep, Turkey, to try to move forward on the evacuations.
Russia's Foreign Minister Sergey Lavrov said al-Qaida-linked militants in Aleppo were refusing to leave the city along the corridors created by the Russians and Syrian forces. He told reporters in Moscow that Russia is "seriously concerned that, despite the gestures of goodwill from Moscow and Damascus," the fighters from the al-Qaida affiliate previously known as the Nusra Front are "refusing to leave the city."
Aleppo's civilians are also being prevented from leaving the eastern, rebel-held part of the city through the corridors, Lavrov added.
The pan-Arab Al-Mayadeen TV aired live footage from the Castello Road showing bulldozers that had opened the road. Buses and ambulances were parked by the roadside, waiting to take evacuees.
But residents in eastern Aleppo have said many won't take advantage of the corridors because there are no guarantees that the evacuees won't be arrested by government forces.
By midday Friday, no evacuations were seen along the Aleppo corridor.
"No one has left the city so far," said Mohammed Abu Rajab, who works at an eastern Aleppo hospital that was repeatedly hit over the past weeks, knocking it out of service. "People are worried they might be detained. There are no guarantees."
Speaking by telephone, he said any evacuations should be coordinated with the United Nations in order for people to feel they can leave safely.
The pause in Aleppo fighting was announced by Russia to allow for the evacuation of civilians and fighters, as well as the wounded. Rebels have rejected the offer, saying it isn't serious.
Before the pause, Aleppo's besieged districts were subjected to relentless Syrian and Russian airstrikes for weeks.
The U.N. human rights chief, meanwhile, said Aleppo is "a slaughterhouse" and urged the Human Rights Council to set aside "political disagreements" to focus on suffering civilians.
Zeid Ra'ad al-Hussein delivered the stark remarks in an address by videoconference to the 47-member U.N.-backed rights body on Friday as it opened a special session on Aleppo called by Britain and others over the crisis in the city.
Zeid, a Jordanian prince, said rights violations and abuses in Syria, in rebel-held eastern Aleppo and beyond "constitute crimes of historic proportions."
He said the "collective failure of the international community to protect civilians and halt this bloodshed should haunt every one of us."
The council was expected to vote later in the day on a resolution that would call for increased monitoring of crimes in Aleppo.
U.S. Deputy Secretary of State Antony Blinken said that situation in Syria, particularly in Aleppo, was "one of the most complicated situations we see on earth."
Even with the humanitarian pause, he said, the Syrian government has refused to give permission for humanitarian assistance to get into to east Aleppo and many other besieged communities. He spoke to the AP Thursday in Paris, on the sidelines of a ministerial summit.
U.N. Secretary-General Ban Ki-moon told an emergency meeting of the U.N. General Assembly on Thursday that nearly 500 people have been killed and almost 2,000 injured since the Syrian government launched its offensive in eastern Aleppo on Sept. 23.
Even as the corridor opened along Aleppo's main artery to the north, the Castello Road, intense clashes and shelling erupted in the Jobar neighborhood in Damascus, activists and residents said. The sound of gunfire and shelling reverberated in the Syrian capital.
The Britain-based Syrian Observatory for Human Rights said there were casualties both among the rebels and the government forces.
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