Israeli Foreign Minister Avigdor Lieberman told Israeli public radio on Sunday that "Egypt must fulfill its obligations in Sinai," but firmly rejected the idea of revising the 1979 Camp David peace accords, which limit the number of troops allowed in the peninsula.

"There is not the slightest possibility that Israel will accept the modification of the peace treaty with Egypt," Lieberman said. "We will not accept any modification of the Camp David accords."

On Friday, an Israeli soldier and three Islamist militants were killed in an exchange of fire near the Egyptian border. The militants had snuck across the border from Sinai into Israel and opened fire on troops, according to the Israeli army.

A Sinai-based Islamist militant group named Ansar Bayt al-Maqdes claimed responsibility for Friday's attack, calling it "a disciplinary attack against those who insulted the beloved Prophet (Muhammad)." The group said the operation was in retaliation to the film "Innocence of Muslims," which has sparked deadly protests across the Islamic world.

'Operation Eagle'

The clash was the latest cross-border incident amid simmering military tensions in the Sinai Peninsula. Egypt has launched a major military offensive in the region in order to root out Islamist militants, who killed 16 members of the Egyptian security forces on August 5 and breached the Israeli border.

Israel has offered tacit support for the Egyptian offensive, called Operation Eagle, while demanding that Cairo remove its troops from Sinai as soon as the region has been stabilized. Militants and traffickers use Sinai as a staging ground to launch attacks against the Jewish state and smuggle goods into the Gaza Strip, which has been blockaded by Israel since 2006.

Peace treaty at stake

Under the 1979 Camp David accords, Israel returned Sinai to Egypt in exchange for a normalization of diplomatic relations with restrictions placed on the number of troops that could be stationed in the peninsula. Israel had captured Sinai from Egypt during the 1973 Arab-Israeli war.

But there is concern in Israel that Egypt, now led by the Islamist Muslim Brotherhood, could use the military offensive to create a fait accompli in Sinai that would force a revision to the terms of the peace treaty.

While the Muslim Brotherhood is more critical of Israel and supportive of the Palestinians than the former US-backed strongman Hosni Mubarak, current Egyptian President Mohammed Morsi has promised to uphold Cairo's international obligations.

slk/mz (AP, AFP)