The Scientific Research Centre in Masyaf has been targeted by the Israelis several times and most recently was in last month, giving rise to reported suspect that Israel is behind the assassination of Asber, according to the watchdog.
The United States along with other Western intelligence agencies have linked CERS to Syria's chemical weapons development capabilities and Iran's Defense Industries Organization, the engine-room of Tehran's weapons industry.
Syria on Tuesday accused Israel of assassinating a top Syrian rocket scientist over the weekend, heightening the growing tensions between the two countries as Syrian government troops restore control over areas bordering Israel. NYT spelled it as Absar, the Israeli newspaper called him Abzar while Syrian official agency described him as Isber.
The Times reports that Israel believes "that Mr. Asbar led the secret unit known as Sector 4 at the Syrian Scientific Studies and Research Center".
Iran had also alleged Israeli involvement in assassinating four nuclear scientists: Masoud Alimohammadi, Majid Shehriari, Rezaeinejad and Mustafa Ahmadi roshan, between 2010 and 2012.
According to Hadashot news, Azbar was tasked with improving the range and accuracy of the Syrian regime's Scud missiles.More news: It's been an afternoon of terror for traders betting against Tesla
"Every day in the Middle East there are hundreds of explosions and settling of scores".
Asbar was not among them, perhaps because he was associated with Syria's missile programme rather than the development of chemical weapons, according to the New York Times.
Under Israeli law, only the prime minister can authorize assassinations, termed "negative treatment" by Mossad.
Asbar headed the Maysaf research centre in Hama, which was hit by Israeli air strikes last month and in September a year ago, the Observatory said.
Israel frequently attacks military targets inside Syria in an attempt to prop up terrorist groups that have been suffering defeats against Syrian government forces. Although no shots have been fired since the 1974 ceasefire, Syrian President Bashar al-Assad continues to press for the return of the territory.