Tehran, Aug 13 (IANS): Iranian Foreign Ministry Spokesman Nasser Kanaani has strongly condemned the deadly "terrorist" attack by the IS militants on a Syrian military bus in east Syria.

Kanaani made the remarks on Saturday in a statement published on the Ministry's website, expressing Iran's sympathy with the Syrian government, people and army.

He attributed the rise in "terrorist" operations and attacks in Syria over the past few months to the continued foreign support for "terrorist" groups with the aim of preventing complete stability and security in Syria, Xinhua news agency reported.

The IS militants ambushed the bus in the desert region of Al-Mayadeen city in Syria's eastern province of Deir al-Zour predawn Friday, killing 33 soldiers, said the Syrian Observatory for Human Rights.

The Friday incident has brought the fatalities due to the increasing IS attacks in the desert region to 420 since the beginning of 2023, according to the war monitor.