JERUSALEM – Three gunmen who crossed into Israel from Egypt’s Sinai Peninsula on Friday were killed in a firefight after killing one Israeli soldier on the border and wounding another, the Israeli army said.

It was the latest of several cross-border attacks that have stirred Israeli concern about a rising security threat from Islamist militants in the Sinai region, where lawlessness has spread since the Egyptian revolution last year.

The gunmen crossed in a mountainous area along the desert frontier where Israel is working to complete a fence, said Capt. Eytan Buchman, an army spokesman.

The steel barrier was intended to keep out African migrants who have streamed into Israel from Sinai in growing numbers in recent years, but it is increasingly seen also as a bulwark against armed infiltrators.

Israeli soldiers who were securing the construction zone were fired on from about 100 yards away as they fetched water for a group of migrants who had reached the border from the Egyptian side, said Maj. Gen. Tal Russo, the chief of the army’s southern command.

An additional Israeli force sent to the scene engaged the gunmen, and during the exchange of fire an explosive belt worn by one attacker detonated, Buchman said. He said the clash unfolded at Mount Harif, about halfway between the Gaza Strip and the southern Israeli resort city of Eilat.