Cairo has complained of a series of Israeli incursions into Egypt's air and sea over the last month. The sources said the Egyptian military was still smarting over the death of at least six soldiers by Israeli fire in late August during a pursuit of suspected Palestinian and Egyptian insurgents in Sinai.

On Sept. 11, an Israel Navy warship was said to have entered Egyptian territorial waters near the Sinai coast. The sources said a Super Dvora patrol vessel strayed 700 meters into Egyptian waters and was immediately recalled by commanders.

"The ship's commander has been prosecuted and imprisoned," an Israeli military spokesman said.

On Sept. 9, an Israeli civilian vessel crossed into Egyptian waters near the Straits of Tiran in the Red Sea. The Egyptian Navy captured the yacht that carried Israeli employees of an unidentified private security company. Hours later, seven Israeli security guards were released by Egypt.

The Israeli incursions were said to have helped spark an Egyptian backlash that led to the takeover of the Israeli embassy in Cairo on Sept. 10. About 1,000 Islamists, believed mobilized by the Muslim Brotherhood, destroyed a concrete barrier around the embassy and ransacked embassy offices.

The sources said Israel has sought to increase border coordination amid Palestinian and Al Qaida-aligned attacks from Sinai. They said the Israeli military has maintained unmanned aerial vehicle and helicopter patrols to detect insurgency infiltration along the southern Egyptian-Israeli border, particularly near the port city of Eilat.

"I do not see Egypt as an immediate threat, but we have to be ready for that and be careful with what we are doing," former Chief of Staff Lt. Gen. Gabi Ashkenazi told the International Institute for Counter-Terrorism on Sept. 12.