BEIRUT: At least 65 people were found shot dead with their hands bound in the city of Aleppo Tuesday in a “new massacre” in the nearly two-yearlong revolt against Syrian President Bashar Assad, activists said.

In New York, peace envoy Lakhdar Brahimi urged the U.N. Security Council to end a conflict that has reached “unprecedented levels of horror,” and warned that Syria was “breaking up before everyone’s eyes.”

The U.N.-Arab League envoy told the council that Assad’s legitimacy had been “irreparably damaged” by the 22-month-old war but that he could still hang on to power, diplomats in a closed briefing told AFP.

Opposition campaigners blamed the government for the massacre in Aleppo, while Syrian state television said the men had been killed by members of the Nusra Front, an Al-Qaeda-linked group, after demanding that its members leave their areas.

The bodies were pulled out of the Qweiq River in the neighborhood of Bustan al-Qasr and opposition fighters said several dozen more victims had yet to be recovered due to the threat of government snipers.

The bodies had bullet wounds in their heads and some of the victims appeared to be young, possibly teenagers, dressed in jeans, shirts and tennis shoes.

Aleppo-based opposition activists said the men had been executed and dumped in the river before floating downstream into the rebel area.

“These are civilians – there is a child among them who was also executed in cold blood,” said Abu Saij, a rebel fighter. “Ordinarily, we would retrieve two or three bodies in a day – never before have we seen such a thing.”

“Yesterday, they [pro-regime forces] were unable to take control of Bustan al-Qasr, and so they took revenge,” Abu Saij continued. “Some of these corpses date back several days, but most were executed recently.”

The bodies, which lacked personal documents, were taken to hospitals for identification by family members.

Elsewhere, rebels captured a vital bridge across the Euphrates River in the eastern city of Deir al-Zor that could cut off regime supplies to the adjoining province of Hassakeh, a watchdog said.

The Britain-based Syrian Observatory for Human Rights said the seizing of the Siyasiyeh bridge and another smaller bridge in the city triggered retaliatory airstrikes from regime forces targeting the two crossings.

Rebels in Deir al-Zor made gains as they battled to control an intelligence complex, including a prison, from which they have freed at least 11 opposition figures, the Observatory said.

In Turkey, a second pair of Patriot missile batteries being sent by NATO countries was now operational, according to a German security official.

The United States, Germany and the Netherlands each committed to sending two batteries and up to 400 soldiers to operate them after Ankara asked for help to bolster its air defenses against possible missile attack from Syria.

The batteries are being stationed around three southeastern Turkish cities and NATO says they will protect 3.5 million Turks from missile attack.

Networks of activists in Syria said at least 160 people were killed in violence around the country, one day after more than 152 people – 74 civilians, 47 rebels and 31 soldiers – were killed, according to the Observatory.

The news of the Aleppo killings came on the eve of a critical donors’ conference in Kuwait, as U.N. officials warn that they lack funds to deal refugee and humanitarian crises that are rapidly spiraling out of control.

Representatives from more than 60 nations are expected at the one-day conference, possibly including envoys from Syrian President Bashar Assad’s main allies Iran and Russia.

U.N. officials, led by Secretary-General Ban Ki-moon, and regional leaders will ask for total pledges of $1.5 billion.

Some 4 million people are estimated to be in need of aid in Syria, including 2 million who are displaced, while more than 700,000 people have been registered as refugees in neighboring states.Speaking ahead of that conference, Kuwait’s Foreign Minister Sheikh Sabah al-Khaled al-Sabah said there was concern Syria could turn into a failed state and put the entire region at risk.

For his part, U.S. President Barack Obama authorized an additional $155 million in humanitarian aid for the Syrian people.

The fresh funding brings his country’s total humanitarian aid to Syria over two years to $365 million, according to the White House. Officials said the money was being used to immunize a million Syrian children, purchase winter supplies for a half-million people, and to help alleviate food shortages.

“The relief we send doesn’t say ‘Made in America,’ but make no mistake – our aid reflects the commitment of the American people,” Obama said in a video announcing the addition funding, which was posted on the White House website.

The EU also promised another 100 million euros ($134 million) for Syrian relief aid, while NGO charity groups, meeting in Kuwait ahead of the conference, pledged $182 million for Syrian civilians affected by the deadly conflict.