A gun battle involving an Egyptian police officer in southern Israel along the Egyptian border left three Israeli soldiers dead Saturday, the army said. It was a rare instance of deadly violence along the frontier.

Lt. Col. Richard Hecht, an army spokesperson, said the fighting began overnight when soldiers thwarted a drug-smuggling attempt across the border.

He said several hours later, two soldiers in a guard post were shot and killed. Their bodies were found after the shooting, when they did not respond to radio communications.

Hecht said the killings appeared to be connected to the thwarted drug smuggling attempt. The army said the Egyptian police officer was killed in a second exchange of fire in which a third soldier was killed.

Hecht said an investigation was being conducted in full cooperation with the Egyptian army. He said troops were searching for other possible assailants.

It was the first deadly exchange of fire along the Israel-Egypt border in over a decade.

The army said one of the killed soldiers was a woman. 

Criminals sometimes smuggle drugs across the border, while Islamic militant groups are also active in Egypt's restive north Sinai.

Israel and Egypt signed a peace agreement in 1979 and maintain close security ties. Fighting along their shared border is rare.

The exchange of fire reportedly took place around the Nitzana border crossing between Israel and Egypt. The crossing is located about 40 kilometers (25 miles) southeast of the point where Israel's border with Egypt and the Gaza Strip converge. It's used to import goods from Egypt destined for Israel or the Hamas-ruled Gaza Strip.

Israel built a fence along the porous border a decade ago to halt the entry of African migrants and Islamic militants who are active in Egypt's Sinai desert.

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• Israel
• Egypt