Syrian government and rebel forces battled near a chemical weapons site in Damascus Sunday, a day after unsubstantiated reports surfaced of an Israeli air strike on a similar site near the capital.

President Bashar Assad’s army counterattacked for the third day in an attempt to drive rebels out of main areas of the capital Damascus. Reuters reported that the battles took place place near the Scientific Studies and Research Center in the Barzeh district of the capital, which has been reported to be a chemical weapons site.

Barzeh, a predominantly working class neighborhood, has become a foothold for rebel forces in the fight against the Assad regime.

In late January, foreign media reports claimed that Israel carried out a series of air strikes that targeted several sites, including a Scientific Studies and Research Center chemical weapons facility and an arms convoy believed to be heading to Lebanon.

Jerusalem never made an official comment on the incident.

Both Israel and Western governments are concerned about the fate of Syria’s chemical weapons stockpiles, one of the largest in the world, and the possibility that such weapons of mass destruction could fall into the hands of Syrian rebels or Lebanon’s Hezbollah.

Sunday’s clashes followed a Maariv report, citing the Free Syrian Army, which claimed that Israeli jets struck a chemical weapons site near the Syrian capital.

Neither the Syrian nor Israeli governments responded to the report, which didn’t specify which site was allegedly struck.

The Free Syrian Army posted a video on YouTube showing smoke rising from what the rebel sources claim to be the chemical weapons site.

According to the FSA report in Maariv, Israeli war planes entered Syrian air space around 6 a.m. Saturday and, after buzzing Assad’s palace and neighborhoods of the capital, struck a chemical weapons research center near Damascus. Syrian air defense batteries reportedly opened fire and Syrian Air Force scrambled to intercept the Israeli planes, but the unspecified number of Israeli fighters returned unscathed.

Sunday’s unconfirmed report of an Israeli airstrike on Damascus came amid rising concern in Jerusalem and Washington about the Syrian government’s possible use of chemical weapons — a measure deemed a “red line” by the Obama administration.

US President Barack Obama has said Syrian use of chemical weapons — or the transfer of Assad’s stockpiles to terrorists — would cross a “red line” that would compel the United States to intervene in the two-year-long civil war.

Israel’s internal security cabinet convened for the first time Sunday since the government was established to discuss the Syrian civil war.

Environmental Protection Minister Amir Peretz (Hatnua) on Sunday called for US military intervention in the ongoing civil war, breaking an order by Prime Minister Benjamin Netanyahu for ministers to keep mum about the Syria issue.

Peretz said action should have been taken long ago, due to the high civilian death toll. “We expect that whoever defines red lines will also do what is needed, first and foremost the US and, of course, the entire international community,” he said.