"There was an attack on the outskirts of the Khalkhalah military airport in Sweida province on Friday," said Rami Abdel Rahman, the head of the Syrian Observatory for Human Rights.
The army has been able to maintain control over the airport and its surrounding areas .At least 15 militants were killed.
Although the Observatory was awaiting confirmation on the identity of the attackers, Abdel Rahman told they were likely to have been terrorist from ISIS.
Khalkhalah airport lies along a major highway that links the government-held provincial capital of Sweida to Damascus.
"The area is important because it's Druze and borders Damascus province," Abdel Rahman told AFP, referring to the minority sect that considers Sweida its stronghold.
Attacks on minority communities have increased with the rise of ISIS, which regularly target such sects in Syria, as well as Sunnis who it alleges have violated its interpretation of Islam.