The Britain-based war monitor said several explosions were heard in the city of Jableh, located 25 kilometers (16 miles) south of Latakia, early on Wednesday as militants launched projectiles at the military facility.
None of the projectiles struck the site as Russian systems intercepted and shot them down, Presstv Reported.
Back on December 23, the Observatory reported several loud booms in the vicinity of Jableh.
Local sources, requesting not to be named, said they were the sounds of Russian air defense systems, which targeted unmanned aerial vehicles as they were flying over the area.
Car bomb kills 3 in Turkish-controlled northern Syrian town
At least three people lost their lives and four others sustained injuries when a car rigged with explosives went off in an area of Syria's northern province of Raqqah, controlled by Turkish military forces and their allied militants ever since they launched a ground offensive against militants from the Kurdish People's Protection Units (YPG).
Syria’s official news agency SANA said the attack took place on Wednesday in the village of Suluk, which is located in the Tal Abyad district of the province.
There was no immediate claim for the act of terror.
A car bomb killed at least eight civilians, including a woman and a child, and wounded 21 others in the same Syrian village on December 23.
On October 9, Turkish military forces and Ankara-backed militants launched a long-threatened cross-border invasion of northeastern Syria in a declared attempt to push YPG militants away from border areas.
Ankara views the US-backed YPG as a terrorist organization tied to the homegrown Kurdistan Workers' Party (PKK), which has been seeking an autonomous Kurdish region in Turkey since 1984.
On October 22, Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan signed a memorandum of understanding that asserted YPG militants had to withdraw from the Turkish-controlled "safe zone" in northeastern Syria within 150 hours, after which Ankara and Moscow would run joint patrols around the area.
The announcement was made hours before a US-brokered five-day truce between Turkish and Kurdish-led forces was due to expire.