Heavy airstrikes struck the Scientific Studies and Research Center, a Syrian government defense laboratory, as well as a military base and warehouse that housed Iranian troops and proxies in Syria. The airstrikes took place at the beginning of this week, according to Syrian state-run media SANA.  

Syrian military sources initially told the media that their air defenses thwarted the attack: “Syrian air defenses intercept an Israeli aggression on a research center in Aleppo province,” SANA reported. But then added that they were assessing the damage caused by the raids.

However, the U.K.-based Syrian Observatory for Human Rights (SOHR), which has been monitoring the civil war, said that the weapons warehouses adjacent to the Syrian defense laboratory were rocked by “violent secondary explosions” in the area. There have been no reports of casualties thus far.

The Scientific Studies and Research Center laboratory is believed to be a facility for the development of chemical weapons for Syria the development of which is aided by Iranian researchers.

The Syrians and their Russian allies have denied that they have used chemical weapons but instead blame anti-regime rebels for chemical weapons attacks.  

With Russia’s assistance, the regime of Assad has turned the tide in the civil war and has regained nearly all of the territory that it had lost.

The SOHR added that further strikes were reported near the town of el-Mayadeen in the Deir ez-Zor region. While no one has claimed responsibility for the attack in Deir ez-Zor, the SOHR said that the most “likely” perpetrator is Israel.

In the past two weeks, there have been seven airstrikes attributed to Israel on Iranian forces in Syria.

Syrian military sources told the Russian-backed Sputnik news outlet that the Israeli aircraft that conducted the Aleppo attack approached from the al-Tanf region of Syria, where the United States military has a base. Al-Tanf base has been a hotspot of activity as the Russians are pouring troops in the surrounding area to check the U.S. The Russians have been active in blocking the U.S. troops from conducting road patrols. The Americans have recently been beefing up their numbers in the region by moving troops from Iraq. 

It is a well-known fact that Iranian-backed militias have long been entrenched in Aleppo province where they have bases and a command center. They have also installed advanced weapons there as part of their growing presence in Syria. The Israelis, who have been adamant about not allowing any Iranian bases close to their borders, have conducted hundreds of airstrikes in the country since the civil war began. 

Israeli defense minister Naftali Bennett told Israeli media last week that Israel would step up its campaign against Iran in Syria.

“We have moved from blocking Iran’s entrenchment in Syria to forcing it out of there, and we will not stop,” Bennett said. “We will not allow more strategic threats to grow just across our borders without taking action. We will continue to take the fight to the enemy’s territory.”

It is believed that Israeli jets also hit Iranian-proxy militias entrenched in the town of al-Bukamal near the border with Iraq, where Iraqi Shia paramilitary groups, backed by Iran, have a strong foothold. Those are the same Iranian-backed militias that the U.S hit with heavy airstrikes in January following dozens of missile attacks on U.S. bases in Iraq — a sequence of events that would lead to the termination by the U.S. of Iranian general Soleimani.