Israel's Benjamin Netanyahu on Thursday stressed the importance of peace with Egypt, as apprehension grew ahead of Egyptian elections expected to produce big wins for the Muslim Brotherhood.

"Israel and Egypt have an interest in preserving peace and stability in the Middle East," the Israeli premier said at media conference with his Romanian counterpart Emil Boc.

"This ensures the sea lanes, economic stability, the quiet and many other things -- for Egypt, for Israel and for other states," he said.

"There are many interests in preserving and advancing the peace, and there are many elements that would like to disrupt it," Netanyahu said.

Both Israel and Egypt were acting "responsibly and seriously against terrorism and against those who violate the peace," he said. "This is a continuing interest both for Israel and any government that arises in Egypt."

Israeli officials, who have largely avoided comment on the Egyptian unrest in which at least 38 have died since Saturday, have begun to show concern as protesters show no signs of giving up their struggle.

On Wednesday, Israel's civil defence minister Matan Vilnai made no secret of his concern about the rise of the Muslim Brotherhood, which is expected to perform well in the elections scheduled to begin on November 28.

"It's our main concern," he told military radio.

Israel was concerned there would be a serious degradation in ties with Cairo once a new government comes to power, he said.

"When the Egyptian government stabilises after a long electoral process, we expect it will seriously undermine the accord," he said.

Israel's Haaretz daily on Wednesday reported that Egyptian officials, including intelligence chief Murad Muwafi, have been at pains to reassure their counterparts in the Jewish state that the 1979 peace treaty is not in danger.