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

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.

The suspect was identified by the Israeli and Egyptian authorities as an Egyptian security officer. The deadly sequence of events may be connected to a thwarted drug smuggling attempt, the Israeli military said.

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.

A gunbattle along Israel’s southern border with Egypt left three Israeli soldiers and an Egyptian officer dead. That’s according to both the Israeli and Egyptian militaries Saturday.