Destroyed Aid Convoy in Syria: What We Know

Almost 48 hours after a deadly attack on an aid convoy in Syria that killed about 20 civilians, Russia still furiously denies its jets or Syrian regime planes were responsible.

Here is what we know about Monday's attack that forced the U.N. to suspend its aid deliveries inside the war-torn country:

- What happened? -

Trucks carrying food and medical equipment from the United Nations and other agencies were unloading aid into a warehouse in Orum al-Kubra, a town in Aleppo province. 

Jens Laerke, a spokesman for the U.N. humanitarian agency (OCHA) in Geneva, said: "Every single partner or party to the conflict" was informed in advance about the delivery. 

According to the Red Cross, the first report that the trucks and warehouse had been hit came at 8:15 pm (1715 GMT), several hours after the Syrian army had declared an end to a week-long partial ceasefire. 

It said "around 20 civilians" had been killed, among them volunteers, as well as Syrian Arab Red Crescent (SARC) staffer Omar Barakat.

Pictures of the convoy published on Twitter by SARC showed several of the trucks draped with blue flags from UNICEF, the U.N. children's agency. 

The raids destroyed at least 18 of the 31 vehicles, the warehouse and much of the aid, the Red Cross said. 

The trucks were carrying sanitation and nutritional supplies for 50,000 people, and nine tonnes of medical aid, including antibiotics and surgical materials, according to UNICEF and the World Health Organization. 

- Who was responsible? -

The Syrian Observatory for Human Rights, a monitor group, reported Monday night that an airstrike had hit the trucks, with a Red Cross spokesman also referring to an air strike.

Although not confirmed, it meant that either Russian or Syrian aircraft were strongly suspected of being responsible as neither opposition groups nor jihadist groups have air power.

Speaking to AFP on Tuesday, an unnamed U.S. official said Washington believed a Russian plane was responsible, saying two Russian SU-24 warplanes had been operating in the area.

But both Russia and Syria have denied responsibility for the attack, with Moscow furious at the "unsubstantiated, hasty accusations" from the U.S.

The Russian military has instead appeared to cast doubt on whether an attack took place, saying that footage from activists at the scene showed damage to the vehicles that did not appear to be caused by an air strike or other munitions.

Russia said its drones had tracked the convoy until it successfully delivered its load, hours before the attack, saying a "fire" that destroyed the trucks which "strangely" coincided with a jihadist attack in the area. 

But Russian military analyst Pavel Felgenhauer said it was impossible for Moscow to draw any conclusions from amateur video of the incident and only an investigation "on the ground" could determine what destroyed the convoy. 

Moscow later released drone footage it said showed a vehicle towing a mortar next to the aid convoy. 

Russia's military did announce its planes had destroyed 16 rebel vehicles elsewhere around Aleppo as it helped Syrian forces beat back a jihadist attack on Monday evening. 

On Tuesday, the Red Cross issued a statement with slightly-altered language which referred to an "attack" on the convoy, and not specifically an air strike.

The main Syrian opposition group said Tuesday it was certain that either Syrian or Russian planes were responsible.

"No one else has aircraft in that area," said leader Riad Hijab in New York. 

Hijab said a member of his High Negotiations Committee (HNC) who was escorting the convoy, had provided him with photographs of the attack that he described as "very precise."

International Committee of the Red Cross head Peter Maurer said an investigation was needed into a "flagrant violation of international humanitarian law."

- What is the fallout? -

Laerke said the U.N. had suspended convoy movements for security reasons, adding that future aid deliveries would depend on a "further assessment of the security situation."

But the Red Cross has not paused deliveries, spokesman Benoit Carpentier told AFP.

Stalled aid deliveries have wreaked havoc across Syria conflict, with the U.N., the Red Cross and others repeatedly demanding unhindered access to civilians in desperate need of life-saving supplies.

Even before the strikes, some 40 U.N. trucks carrying relief supplies destined for rebel-held east Aleppo had remained stuck in a customs zone between the Turkish and Syrian borders since early last week.