"Several strikes on Masyaf have been attributed to Israel in recent years, the last of which was on July 22".
The NYT quoted "a senior official from a Middle Eastern intelligence agency" who on Monday said it was at least the fourth time in three years that Israel has assassinated an enemy weapons engineer. Separate western reports have also indicated Iranian missile operation at the site.
If the assassination was carried out by Mossad, it was the latest in a long line of Israeli attacks targeting Syrian weapons capabilities and development.
Israel frequently attacks military targets inside Syria in an attempt to prop up terrorist groups that have been suffering defeats against Syrian government forces.
It's believed that the deceased had close ties with Al-Assad as well as the Iranian regime and, according to British-based Syrian Observatory for Human Rights, the unit being used for chemical weapons development.
A branch of the centre outside Damascus was among the targets of US strikes in April and the US Treasury Department has imposed sanctions on the institution since 2005. The blast also killed his personal driver.
According to al-Watan daily newspaper, Syrian authorities had twice detained cells of local suspects allegedly recruited by Mossad who were engaged in monitoring Asbar's movements.
The Abu Amara Brigades released a statement on their Telegram online channel that said they "planted explosive devices" which detonated and killed Asber.
The attack came as Syrian troops regained territory along the 1974 demarcation line separating the Israeli-occupied Golan Heights from Syria.