The official Syrian news agency says Israeli missiles have struck a scientific research center on the outskirts of Damascus in an overnight attack.
If confirmed, the attack Sunday morning inside Syria would be the second by Israeli since early Friday.
The SANA news agency reported the latest attack Sunday, a day after anonymous Israeli officials reported that Israel struck a missile shipment believed headed for the Lebanese-based militant group in the overnight hours early Friday. The Israeli government has not confirmed either report. There is no sign Israeli warplanes entered Syrian airspace.
On Saturday, U.S. President Barack Obama said in an interview with the Spanish-language network Telemundo that Israel is justified in protecting itself from advanced weapons shipments to terrorist groups like Hezbollah.
He did not directly comment on the reports of an Israeli airstrike. He said he would let Israel "confirm or deny whatever strikes that they have taken."
Hezbollah is allied with Syrian President Bashar al-Assad. The militant group, supported by Iran, waged a brief war with Israel in 2006. This would be the second time Israel has conducted airstrikes against Syria this year. Israel said it attacked a weapons convoy in Syria believed headed for Hezbollah in January.