BEIRUT — The Latest on Syria’s conflict (all times local):

11 p.m.

A senior U.S. official says that Washington has determined with a very high degree of confidence that an attack on a humanitarian aid convoy in Syria on Monday was carried out by a Russian piloted aircraft.

The assessment laid more deliberate blame on Moscow for the strike on the Syrian Arab Red Crescent convoy, which killed 20 civilians.

Washington had said Tuesday that Russia was to blame, but that the strike delivered by a Russian-made Su-24 could have been carried out by Russia or Syria. Both militaries use Su-24 fighter jets.

Officials are now saying the U.S. has gathering enough intelligence to say that it was Russia, not Syria, that launched the airstrike.

The officials spoke on condition of anonymity because they weren’t authorized to discuss intelligence information publicly.

— Lolita C. Baldor in Washington

8:45 p.m.

The United Nations says it will resume aid convoys within Syria after an attack on a convoy killed 20 people and prompted a temporary suspension.

Jens Laerke, the spokesman for the U.N. humanitarian aid agency, says Wednesday that “several” convoys are expected as early as Thursday, but didn’t specify where. He said the convoys would not go to Aleppo.

An attack on Monday night in Aleppo province on a warehouse of the Red Crescent where U.N. aid was delivered that day killed 20 people and destroyed most of the delivery.

In response, the U.N. suspended overland aid operations to priority areas in Syria pending a full security assessment.

Laerke acknowledged that a full assessment had not been completed, but said the planned deliveries would take place now on a case-by-case basis.

7:30 p.m.

Syrian opposition activists say suspected government airstrikes in the northern city of Aleppo and the rebel-held Idlib province have killed 23 civilians, including at least five children.

The Britain-based Syrian Observatory for Human Rights says at least 11 civilians, including three children and three women, were killed Wednesday during air raids on several rebel-held neighborhoods of Aleppo. The Observatory says the toll is likely to rise because rescue efforts are ongoing.

Ibrahim Alhaj, a member of the volunteer first responders known as the Syria Civil Defense, says 24 people were killed in the Aleppo strikes. Mohammed Abu Jaafar, from the local forensics team, said one of the 24 was a fighter.

In nearby Idlib, the Observatory said 12 civilians, including two children, were killed in at least eight air raids.

A U.S. and Russian-brokered cease-fire that went into effect nine days ago is on the brink of collapse, with the government and the rebels alleging dozens of violations.

6:45 p.m.

The Russian military says a U.S. drone was flying over the area when an aid convoy was attacked in Syria on Monday.

Defense Ministry spokesman Maj. Gen. Igor Konashenkov said Wednesday the Predator drone, which took off from the Incirlik base in Turkey, flew into the area where the convoy was attacked near the Syrian city of Aleppo minutes before it came under fire.

He says the drone left the area about a half-hour after the attack.

U.S. officials said Tuesday that two Russian Su-24 aircraft were flying over the area at the moment of the attack. Russia has denied that its own aircraft or Syrian warplanes struck the convoy.

The attack drew international condemnation and prompted the U.N. to suspend aid shipments in Syria, where some 6 million people live in besieged or hard-to-reach places.

6:10 p.m.

U.S. Secretary of State John Kerry wants all aircraft over key humanitarian routes in northern Syria grounded in order to facilitate desperately need aid deliveries.

Kerry told the U.N. Security Council on Wednesday that such a step could restore credibility to efforts to end the five-year civil war and “give a chance for humanitarian assistance to flow unimpeded.”

A U.S.-Russian cease-fire that went into effect nine days ago has all but collapsed. The U.N. suspended aid deliveries after a strike on a humanitarian convoy this week.

5 p.m.

The Russian defense minister says the navy will send its sole aircraft carrier to the eastern Mediterranean.

Sergei Shoigu said Wednesday that the Admiral Kuznetsov will join other Russian ships near Syria’s shores. He didn’t specify when it will be deployed, but Russian media reports have said the mission is planned for the fall.

The Soviet-built Admiral Kuznetsov, the only aircraft carrier in the Russian navy, has recently been re-equipped with new fighter jets.

Russia has waged a yearlong air campaign in Syria that has shored up President Bashar Assad and allowed his troops to seize some key ground. Last week, Moscow and Washington brokered a cease-fire in Syria, which is now teetering on the brink amid renewed fighting and an attack on a humanitarian convoy.

4:50 p.m.

The U.N. Security Council has taken up Syria’s civil war as a temporary truce unravels and international tensions rise.

A day after the U.S., Russia and other powers sought to keep the week-old cease-fire alive, the same actors are debating the conflict in a public setting.

Moscow backs Syrian President Bashar Assad’s government, while Washington supports many of the rebel factions fighting to topple him. Both say they’re committed to fighting the Islamic State group and al-Qaida-linked militants.

A relief organization reported five medical staff killed in an airstrike in northern Syria on Tuesday night, the latest in a series of attacks on humanitarian workers.

A strike on a Syrian Red Crescent aid convoy earlier this week prompted international condemnation. The U.N. called it a deliberate attack. U.S. officials say they believe Russia carried out the strike. Russia denies responsibility.

3:20 p.m.

A medical relief organization says an airstrike in northern Syria hit a mobile emergency unit, and not a medical facility.

Dr. Oubaida Al Moufti, vice president of the International Union of Medical Care and Relief Organizations, says five staff members were killed when its ambulances were hit. He told The Associated Press in Paris on Wednesday that the team was bombed while responding to an earlier airstrike targeting militants from the al-Qaida-linked Fatah al-Sham Front.

The Paris-based aid group initially said the attack Tuesday night leveled a medical triage facility it operates in rebel-held territory outside the contested city of Aleppo.

The group, known by its French initials UOSSM, said three nurses and two ambulance drivers were killed.

2:50 p.m.

Syrian state TV says a military warplane has crashed and the pilot has been rescued after carrying out a combat mission against Islamic State group militants northwest of the capital, Damascus.

State TV, quoting an unnamed military official, says the pilot has been rescued but doesn’t say what caused the plane to crash in the Qalamoun mountains, an area that straddles the border with Lebanon.

The IS-affiliated news agency Aamaq said earlier the group’s militants downed the plane in eastern Qalamoun after the aircraft carried out four raids against it. The agency said the plane crashed in an area controlled by either the government or rebel factions.

The militant group downed a government aircraft Sunday in the eastern Deir el-Zour province.

2:20 p.m.

A Syrian monitoring group says a warplane has crashed northwest of the capital, Damascus, as Islamic State group militants claim they downed it.

The Britain-based Syrian Observatory for Human Rights says the fate of the pilot remains unclear. It says it was unclear if the warplane was downed Wednesday or had technical problems.

The Observatory says the plane crashed in the eastern Qalamoun mountains, northwest of Damascus.

The IS-affiliated news agency Aamaq says the group’s militants downed the plane in eastern Qalamoun, after the aircraft carried out four raids against it. The agency says the plane crashed in an area controlled by either the government or rebel factions, indicating it would not have pictures of the aircraft.

IS says it downed a Syrian government warplane. There was no immediate comment from the government.

10:30 a.m.

A medical relief organization says four of its staff have been killed in an attack on a medical facility in Syria.

The International Union of Medical Care and Relief Organizations says an airstrike Tuesday night in northern Syria leveled a medical triage point in rebel-held territory outside the contested city of Aleppo.

The Britain-based Syrian Observatory for Human Rights monitoring group puts the toll at 13 dead, among them four nurses and paramedics and nine rebel fighters, some of them belonging to the al-Qaida-linked Fatah al-Sham Front.

It says the triage point was located in the rebel-held town of Khan Touman, south of Aleppo.

There were no reports on who was behind the strike.