At least 112 people were killed in a drone attack on a military academy in Homs that struck minutes after the Syrian Defence Minister left the complex, according to a war monitor and pro-Damascus officials.
Syrian state TV reported a “terrorist attack” at the site on the Telegram messaging app, saying there were “a large number of casualties”.
Preliminary reports suggested at least 50 people had been killed and another 150 wounded, before the death toll then rose later on Thursday evening.
The Syrian Observatory for Human Rights said the attack took place shortly after a graduation ceremony had ended.
Leading army and Defence Ministry officials were also present at the ceremony, the war monitor reported.
Syrian Defence Minister Ali Abbas was wounded in the strike on Homs Military Academy, Syrian security sources told Reuters.
However,Syrian TV reported Mr Abbas left the site immediately after the ceremony ended, with the attack taking place 20 minutes later.
The drone attack took place as graduating officers were taking photos with their families, leading to the deaths of several children, it said.
“After the ceremony, people went down to the courtyard and the explosives hit. We don't know where it [the attack] came from, and corpses littered the ground,” a witness told Reuters.
Survivors were later moved to the basement of Homs military hospital. The Defence Ministry said the attack was carried out by “armed terrorist organisations supported by well-known international parties”.
“This occurred immediately after the end of the ceremony, which resulted in the death of a number of martyrs, both civilians and military personnel, and dozens of wounded, including critical injuries among the invited families, including women and children,” Sana reported, citing the Defence Ministry.
“The General Command of the Army and Armed Forces considers this cowardly terrorist act an unprecedented criminal act and affirms that it will respond with full force and decisiveness to these terrorist organisations wherever they are found.”
There was no immediate claim of responsibility for the attack.
Regime forces have previously been the targets of Israeli drones, including near Homs, but Israel rarely acknowledges responsibility.
In July, Damascus said it had shot down a number of Israeli missiles near Homs.
The army is also often the target of rebel and terrorist groups, including ISIS and Al Qaeda-backed militants.
Eleven regime troops were killed and many others wounded in a militant attack in August.
A bloody day in Syria
The attack on the military base was one of several outbreaks of violence in Syria on Thursday.
At least seven people were killed in Turkish air strikes on military and infrastructure sites in north-east Syria, according to Kurdish officials.
Six people were killed in a strike on a brick factory, which also killed a worker at another complex.
Ankara has stepped up aerial attacks on Kurdish-ruled areas of north-east Syria and northern Iraq following a terror attack in the capital on Sunday, when a bomb was detonated outside the Turkish interior ministry.
Regime shelling also killed five civilians in Aleppo province, according to activists and emergency workers.
The UN has said it is deeply concerned by rising violence in Syria, which is currently in the midst of some of the worst fighting in recent years.
“The Secretary General strongly condemns all violence in Syria and urges all parties to respect their obligations under international law,” spokesman Stephane Dujarric told reporters.
