According to the Syrian Observatory for Human Rights, rebels in the Syrian Golan region shot down a Syrian Army helicopter not far from the Israeli border. Both soldiers on board the helicopter were killed in the attack.
This area, southwest of Damascus, has been a common site of fighting between the government and rebels in recent months. The area remains controlled by Islamist factions, though the government has it surrounded.
According to the Observatory’s report, a guided missile was fired at the helicopter to shoot it down. The exact type of missile or exactly which faction fired it are as yet unclear, though if it turns out to be a US-provided missile this may be another source of tension.
Not that this is necessarily the case. While the US has indeed armed a lot of the rebel factions, the Syrian War started around the same time the Libyan regime change happened, and that too put a lot of anti-aircraft weapons on the black market.