Israel killed a top commander from the Iranian-backed Palestinian militant group Islamic Jihad in a rare targeted strike in the Gaza Strip on Tuesday, while militants responded by firing rockets at Israeli cities, including Tel Aviv.

In the most serious escalation in months, an Israeli missile attack also targeted the home of an Islamic Jihad official in Damascus, killing two people including one of his sons, Syrian state media said.

Islamic Jihad said the target was the home of political leader Akram Al-Ajouri.

Hours later, sirens sounded in central Israeli cities, including the commercial capital of Tel Aviv the military and witnesses said, warning of possible rocket launches from the Gaza Strip.

Israel’s home-front command ordered schools shut across southern and central Israel, and instructed civilians to stay at home and not go into work unless it was vital and public shelters were opened.

There were no immediate reports of casualties. Israeli media reported that some of the rockets were intercepted.

The slaying of Baha Abu Al-Atta in his Gaza home looked likely to pose a new challenge for Gaza’s ruling Hamas faction, which has mostly tried to maintain a truce with Israel since a 2014 war.

Israel said Al-Atta had carried out a series of cross-border attacks and was planning more.