Israel ordered its state-run electricity company to halt supply to the Gaza Strip on Saturday after the Palestinian militant group Hamas launched a surprise attack on Israel, the energy minister said.

“I have signed an order instructing (Israel) Electric Company to stop the electricity supply to Gaza,” Energy Minister Israel Katz said in a statement.

At least 150 Israelis have been killed in the attacks launched by the Palestinian movement Hamas.

Israel said the Iran-backed group had declared war as its army confirmed fighting with militants in several Israeli towns and military bases near Gaza and Prime Minister Benjamin Netanyahu vowed to retaliate.