An Israeli working on the border fence in the Sinai was killed by a squad of terrorists who crossed over from Egypt into Israel. The attack occurred as Egyptians were voting for a new president, who appears at this point to be the Muslim Brotherhood candidate Mohammed Morsi.
The Sinai attack, launched soon after Egypt's Muslim Brotherhood declared victory in the country's presidential election, raised Israeli concerns about lawlessness in the area since the fall of former President Hosni Mubarak in 2011.
"We can see a disturbing deterioration in Egypt's control of the Sinai's security," Israeli Defense Minister Ehud Barak said, commenting on the attack.
"We are waiting for the election results. Whoever wins, we expect him to take responsibility over all of Egypt's international commitments, including the (1979) peace treaty with Israel and security arrangements in the Sinai, and to put an end to these attacks swiftly," he told reporters.
Three gunmen crossed into Israel from the Sinai desert, the Israeli military said. Spokesman Yoav Mordechai said "a terrorist squad opened fire and possibly also fired an anti-tank rocket at an area where (Israel) is constructing the border fence".
Soldiers who rushed to the scene killed two of the militants but could not find the third, who may have returned to Egypt, the military said.
A military source said the worker killed was an Arab citizen of Israel. There was no immediate claim of responsibility for the attack, about 30 kilometers (18 miles) from the Gaza Strip.
Israel is building a fence along the frontier to curb an influx of African migrants and boost security, and hopes to complete it by the end of the year. It will run along most of the 266 km (165 miles) from Eilat, on the Red Sea, to the Gaza Strip.
During the Mubarak era, the Egyptian military patrolled the Sinai in order to prevent these kinds of attacks. But since the fall of the dictator, several incidents - including a deadly attack last summer that killed 8 Israelis - have forced Israel to construct the border fence.
It is doubtful that a Muslim Brotherhood government would do any better at keeping Egypt's word about Sinai security given in the Camp David Accords.