In one of the bloodiest single attacks on the army since the start of Syria's war in 2011, Thursday's assault came just after the ceremony attended by officers and their families, killing and wounding both military personnel and civilians.
State media said Friday that 89 had died, including 31 women and five children, with 277 other people wounded.
Dozens of distraught victims' relatives gathered outside the Homs military hospital since the early morning, an AFP correspondent said.
A woman in a black dress adorned with white flowers was overwhelmed with grief at the loss of her son.
"Do not go, my beloved," she cried. "This sleep does not befit you."
The Syrian Observatory for Human Rights, a Britain-based monitor, reported a heavier toll of 123 dead, including 54 civilians, 39 of them women and children. It said at least 150 people were wounded.
In a rare move since the war broke out, the government has declared three days of mourning starting Friday, with flags flying at half-mast.
Defence Minister Ali Mahmoud Abbas attended the first funerals for around 30 people, including both military and civilians.
Military personnel saluted as rows of caskets draped in Syrian flags were carried one by one and placed into ambulances for transportation for burial.
Panic and chaos
Videos circulating on social media have showed panic and chaos during the attack, with people falling to the ground and others pleading for help.
"Martyrdom, dignity and national pride come at a great cost," Abbas told victims' families, according to a statement broadcast on state television.
The blood of those who died "is dear, but the nation is dearer", he added.
Abbas had been present at the graduation ceremony but left just minutes before the attack, eyewitnesses and the Observatory said.
At the military hospital, Khawlah, 33, ws searching among the coffins for her brother.
"Amjad did not die, I died," she told AFP, grief-stricken.
No group has claimed responsibility for the assault, but the Syrian army has accused "armed terrorist organisations" of the attack with "explosive-laden drones", vowing to "respond with full force".
The Syrian army on Thursday began a bombing campaign on opposition-held areas in the country's northwest in apparent retaliation.
The Observatory said Friday that 15 civilians had been killed, adding that Russian warplanes carried out at least five strikes in the Idlib area.
Russian President Vladimir Putin condemned the academy attack and expressed his condolences to his Syrian counterpart Bashar al-Assad, the Kremlin said Friday.
"We intend to keep up our close cooperation with our Syrian partners to fight all forms... of terrorism," Putin said, quoted in a Kremlin statement.
Homs province was a key opposition stronghold in the early days of Syria's conflict. The government regained control over the province in 2018.
Swathes of Idlib province and areas bordering the provinces of Aleppo, Hama and Latakia are controlled by Hayat Tahrir al-Sham, led by Al-Qaeda's former Syria branch.
HTS and the Islamic State jihadist group have used drones to attack government-held areas and Syrian and Russian military targets, including in recent months, according to the Observatory.
United Nations chief Antonio Guterres was "deeply concerned" over the drone attack and "reports of retaliatory shelling", his spokesman said.
The attack came as Turkey on Thursday struck at least 21 sites including civilian infrastructure and in northeast Syria, according to security forces in the semi-autonomous Kurdish administration that controls the area.
The forces reported 11 dead, including six of its members and five civilians.
AFP correspondents and the Observatory said the bombing in the northeast subsided overnight.
Turkey's defence ministry said Thursday that Ankara's forces had carried out air strikes in northern Syria, destroying 30 targets, including "shelters, depots and storage sites".
Pentagon spokesman Pat Ryder meanwhile said US F-16 warplanes over Syria had shot down a Turkish drone on Thursday, deeming it "a potential threat" after it approached "less than a half kilometre from US forces" near Hasakeh.
The conflict in Syria has killed more than half a million people since it began in 2011, spiralling into a devastating war involving foreign armies, militias and jihadists.