Three Israeli soldiers have been killed by an Egyptian security officer in exchanges of fire on the Israeli side of the border.
The armed forces of both countries say they are jointly investigating the unusual incident.
The Israeli military has said the shootings were assumed to be connected with a drug smuggling operation it had thwarted overnight.
According to the army, two Israeli soldiers - a man and woman - posted in a remote spot along the border were shot dead early on Saturday morning.
Their bodies were discovered after a senior officer was unable to contact them by radio.
Hours later, after a search operation, the alleged attacker was encircled and there was a shootout, the Israeli military says.
A third soldier was killed, along with the gunman, who it said was an Egyptian policeman. Another soldier was wounded in that exchange.
