Three Israeli soldiers and an Egyptian security officer were killed near the countries' border on Saturday, Israel and Egypt said, in an incident whose details remained unclear but which the countries said they were investigating jointly.

Israel said the Egyptian border guard crossed into Israel and killed the three soldiers before he was fatally shot by troops.

Israel said the Egyptian border guard crossed into Israel and killed the three soldiers before he was fatally shot by troops. Egypt said he had been chasing drug smugglers when he entered Israel.

Israeli Prime Minister Benjamin Netanyahu on Sunday called the killing of three soldiers by a member of the Egyptian security services a terrorist attack and demanded a full joint investigation with Cairo.

Israel's military says a gunbattle involving an Egyptian police officer in southern Israel along the Egyptian border has left three soldiers dead. It was a rare instance of deadly violence along the frontier.

Three Israeli soldiers were killed Saturday in a terrorist incident along the Egyptian border, military officials announced.