By Agence France-Presse
"The rockets that were launched against Israel... we know that the orders, incentives were given from Damascus with the clear involvement of the Iranian Revolutionary Guards' Quds Force," army spokesman Lieutenant Colonel Jonathan Conricus said, referring to the Guards' foreign operations unit.
Conricus told reporters Israel's response "is not limited geographically."
At least 39 rockets have been fired at southern Israel by the Islamic Jihad group since late Friday, with 17 of them intercepted by the Iron Dome air defence system, and the rest hitting open fields, the army said.
Israeli aircraft carried out extensive retaliatory strikes in Gaza, targeting approximately 90 sites belonging to the territory's Islamist rulers Hamas.
Conricus said that Israel held Hamas responsible for the fire, even though it was carried out by Islamic Jihad at the behest of Syria and its ally Iran.
"We hold Hamas responsible for everything coming from Gaza," he said.
On Friday, six Palestinians died in renewed clashes on the Gaza-Israel border, while Hamas said Egypt was seeking to negotiate a return to calm.