Explosions shook Damascus early on Sunday and Syrian state television said Israeli rockets had struck a military research center on the outskirts of the capital.

The blasts occurred a day after an Israeli official said his country had carried out an air strike targeting a consignment of missiles in Syria. The research center hit on Sunday was also targeted by Israel in January.

“The new Israeli attack is an attempt to raise the morale of the terrorist groups which have been reeling from strikes by our noble army,” Syrian television said, referring to recent offensives by President Bashar al-Assad’s forces against rebels.

The British-based Syrian Observatory for Human Rights quoted eyewitnesses in the area as saying they saw planes in the sky at the time of the explosions. It said the blasts hit the Jamraya military center and a nearby ammunition depot.

There was no immediate comment from Israeli officials on Sunday’s explosions. “We don’t respond to this kind of report,” an Israeli military spokeswoman told Reuters.

In Washington, the U.S. State Department and Pentagon had no immediate comment and the Israeli Embassy declined comment.

Assad is battling a two-year uprising that began with mainly peaceful protests that were met with force and grew into a bloody civil war in which the United Nations says at least 70,000 people have been killed.

Video footage uploaded onto the Internet by activists showed a huge ball of fire rising into the night sky on the edge of the Syrian capital.

(Reuters)