The Israeli Air Force bombed a chemical weapons compound near Damascus, according to the Free Syria Army, one of the largest opposition forces in the ongoing Syrian civil war.
The validity of the attack, which the group claims took place Saturday, has not been confirmed, and a second report of an assault on the compound did not mention Israel.
According to the UPI, a Syrian army air defense battery fired on the Israeli planes to no effect; and the jets circled Syrian dictator Bashar al-Assad's palace and other key targets, before bombing the compound.
Neither al-Assad's Damascus-based regime, nor the government of Israeli Prime Minister Benjamin Netanyahu, have commented on the reports.
Media reports confirmed heavy fighting in the area of the compound, termed the Scientific Studies and Research Centre.
This would not be the only recent incursion by Israel into the Syrian conflict. In January, the AIF attacked a convoy outside Damascus, that the Jewish state claimed was carrying weapons to the Shi'ite militant group Hezbollah in Lebanon.
Formed in 2011, the Free Syria Army is a secular opposition group formed of civilian volunteers and uniformed Syrian military deserters.