U.N. chief speaks of “grisly reports” from Syria.

Reuters - U.N. Secretary-General Ban Ki-moon said on Friday he had received “grisly reports” that Syrian government forces were arbitrarily executing, imprisoning and torturing people in the battle-scarred city of Homs after rebel fighters had fled.

The Baba Amro district of Homs became a symbol of resistance to Syrian President Bashar al-Assad after government troops surrounded it with tanks and artillery and shelled it intensively for weeks, killing and wounding civilians cowering in its ruined buildings.

Rebels withdrew on Thursday in a key moment in the year-old uprising against Assad. An official at Syria’s Ministry of Foreign Affairs and Expatriates said the army had “cleansed Baba Amro from the foreign-backed armed groups of terrorists.

Opposition activists said Syrian troops were hunting down and killing insurgents who had stayed to cover their comrades’ retreat.

“A major assault on Homs took place yesterday,” Ban told the 193-nation U.N. General Assembly in New York. “Civilian losses have clearly been heavy. We continue to received grisly reports of summary executions, arbitrary detentions and torture.”

Syria’s U.N. Ambassador, Bashar Ja’afari, said Ban’s remarks included “extremely virulent rhetoric which confines itself to slandering a government based on reports, opinions or hearsay.”

“The secretary-general is not duly informed,” he said, reiterating that the Syrian opposition consisted of “armed terrorist groups.”

The International Committee of the Red Cross said an aid convoy had reached the bombarded Baba Amro area, under siege for 26 days, but was not allowed to enter.

“It is unacceptable that people who have been in need of emergency assistance for weeks have still not received any help,” ICRC President Jakob Kellenberger said in a statement.

“We are staying in Homs tonight in the hope of entering Baba Amro in the very near future.”

Ban urged Damascus to grant immediate access for aid workers, describing the images of death coming out of the country as atrocious.

One activist in Homs told Reuters: “The Syrian army was holding the convoy up because they want to clean up after what they have done in Baba Amro.” As with other activist reports from Homs, this could not be independently confirmed.

“All men who remained in the neighbourhood aged between 14 and 50 were arrested. We fear they will be massacred. Where is the world?” said one activist.

“The massacres are continuing. They are torturing them and killing (detainees) one by one. They are executing them in batches,” another activist, who left Baba Amro on Friday, told Reuters via Skype.

Many fighters out of the 2,000 who were based in Baba Amro were killed and wounded in the onslaught, they said, adding that a final toll was impossible to give because of the heavy shelling and siege. Hundreds were reported to have fled.

The ICRC convoy of seven trucks carrying food and other aid supplies left Damascus early on Friday for Homs, where it met local volunteers and ambulances of the Syrian Arab Red Crescent prepared to treat and evacuate the sick and wounded.