“This is a severe and dangerous escalation. Our defensive and offensive capabilities are at the highest level of readiness ahead of this large-scale attack from Iran,” said Israel’s military spokesperson Rear Admiral Daniel Hagari.

Israeli Prime Minister Benjamin Netanyahu, whose official jet took off shortly after the attack began, convened the war cabinet at a military headquarters in Tel Aviv, his office said.

Israel’s military said sirens would sound in any threatened areas and that its defenses were poised to deal with the drones, which it said were “explosive.”

“We are used to having around 20 seconds to get to shelters when missiles come in. Here, the warning comes hours ahead of time. It naturally raises the anxiety level among the Israeli public,” said Nir Dvori, a Channel 12 TV correspondent on social media.

Israel’s military told residents of the Israeli-occupied Golan Heights to stay close to bomb shelters, putting the area on standby for possible impact from drone strikes.

Israel and Lebanon said they were closing their airspace on Saturday night. Jordan, which lies between Iran and Israel, had readied air defenses to intercept any drone or missile that violated its territory, two regional security sources said.

Residents in several Jordanian cities said they heard heavy aerial activity.

Syria, an ally of Iran, said it was putting its ground-to-air defense systems around the capital and major bases on high alert, army sources there said.

The European Union, Britain, France, Mexico, Czechia, Denmark, Norway and the Netherlands all condemned Iran’s attack.

Israel has been bracing for an Iranian response to the Damascus consulate strike since last week, when Iran’s Supreme Leader Ayatollah Ali Khamenei said Israel “must be punished and shall be” for an operation he called equivalent to one on Iranian soil.

Biden said on Friday that his only message to Iran was “Don’t”, but added that “we are devoted to the defense of Israel.”

Iran’s main ally in the region, the Lebanese Shi’ite group Hezbollah has been exchanging fire with Israel since the Gaza war began on Oct. 7, said early on Sunday it had fired rockets at an Israeli base.

Earlier on Saturday, Iran’s state-run IRNA news agency reported that a Guards helicopter had boarded and taken into Iranian waters the Portuguese-flagged MSC Aries.

MSC, which operates the Aries, confirmed Iran had seized the ship and said it was working “with the relevant authorities” for its safe return and the wellbeing of its 25 crew.

MSC leases the Aries from Gortal Shipping, an affiliate of Zodiac Maritime, Zodiac said in a statement, adding that MSC is responsible for all the vessel’s activities. Zodiac is partly owned by Israeli businessman Eyal Ofer.

Israeli Foreign Minister Israel Katz accused Iran of piracy.