The initial reports coming out of Syrian media was that the base was hit by unidentified aircraft, with some reports attributing the attack to Israel. Later, reports said that the explosion was caused by an accident at the facility.
The Iranian base, located in the Jabal Azzan region south of Aleppo, is the largest in the country.
Hezbollah media sources denied the reports and said that the explosions at the site resulted from explosives detonating in a warehouse.
“A powerful explosion went off late Saturday in an area of southern Aleppo province,” the Britain-based Syrian Observatory for Human Rights monitoring group said.
The war monitor’s head, Rami Abdel Rahman, said the area was known to host Iranian forces deployed in Syria to support President Bashar Assad’s regime as well as allied Afghan fighters from the Fatemiyoun Brigade.
Seven Iranian military personnel were killed last week in an air strike on a Syrian air base which was blamed on Israel.
Jerusalem did not confirm or deny mounting the raid, but Israeli officials said the Tiyas, or T-4, air base near Homs was being used by troops from Iran, and that Israel would not accept such a presence in Syria by its arch foe.
Israeli Prime Minister Benjamin Netanyahu addressed Iran's entrenchment in Syria during a cabinet meeting on Sunday. Relying information from a phone call he held with his British counterpart Theresa May, Netanyahu said he: "reiterated that the element that is undermining the Middle East more than any other is Iran, and that President Assad must understand that when he allows Iran and its proxies to establish its military presence in Syria, he is endangering Syria and the stability of the entire region."
Israel said in February it had intercepted an Iranian drone launched from Syria, and carried out air strikes against air defenses and Iranian targets in the country. Iran denied at the time the downing of its drone in Israel.