At least 100 people were killed in a drone attack that struck a military academy in Syria's Homs province while a cadet graduation ceremony was underway, state media reported on Friday.

Citing a statement from the General Command of the Armed Forces, Syria's state-run SANA news agency said several drones carrying explosives targeted the academy just after the ceremony ended on Thursday afternoon, reports the BBC.

The armed forces "considers this act an unprecedented criminal one, and affirms that it will respond with full force and determination to these terrorist groups wherever they are", the statement added.

In another report, SANA quoted Health Minister Hassan al-Gabbash as saying that the attack had injured more than 200 people, while the victims included and six women and six children.

Drone attack on cadet graduation ceremony in Syria kills 100

The cadets' families, and women and children were among the dead, it added.

So far, no individual or group has claimed the attack, the BBC reported.

According to the UK-based Syrian Observatory for Human Rights (SOHR), the country's Defence Minister had attended the ceremony but left minutes before the attack.

Describing the attack as "horrific", UN special envoy for Syria Geir Pedersen has called on all parties to the decades-long conflict to "exercise the utmost restraint".

"All sides must respect their obligations under international law and ensure the protection of civilians and civilian infrastructure. Today's developments further highlight that the status quo in Syria is unsustainable and that, in the absence of a meaningful political path... I fear we will only see further deterioration, including in the security situation," the BBC quoted the envoy as saying late Thursday.

More than half a million people have been killed by the civil war that erupted after President Bashar al-Assad cracked down violently on peaceful pro-democracy demonstrations in 2011.

Some 6.8 million people are internally displaced, while another 6 million are refugees or asylum-seekers abroad.

(With inputs from IANS)