Prime Minister Benjamin Netanyahu warned Hamas on Tuesday that Israel is “preparing” an attack on the terror group that would be “the surprise of their lives if they don’t come to their senses” and stop the launching of booby-trapped balloons from the Gaza Strip.

Massive numbers of balloons laden with explosives have been dispatched across the border over the past several weeks after a relative lull. In the past, Israeli farms have been set on fire from these explosives. Children have been warned against approaching the balloons at the risk of injury or death.

“I do not rush to make war,” said the Israeli premier in an interview with Israel’s Channel 20, but if the attacks don’t stop, he warned, “it’s just a matter of time until we will activate that surprise. I will not reveal it here but it’s different from anything that came before and remember everything that I said.”

Asked by an interviewer whether such an Israeli military action could come soon, Netanyahu replied: “It depends on them.”