Egypt's judiciary said Monday it was extending ousted president Mohammed Morsi's detention for a further 15 days pending an investigation into his collaboration with Hamas.

Morsi, overthrown by the military on July 3, was placed in detention on July 26 over his links with the Palestinian Islamist militant group, which rules neighboring Gaza.

Egyptian air strikes in the Sinai Peninsula killed at least eight militants and destroyed a weapons depot, the military and local residents said on Sunday.

The overnight strikes against "a terrorist group" responsible for killing police and army troops in north Sinai left "25 people dead and injured", army spokesman Colonel Ahmed Aly said.

Supporters of ousted Egyptian president Mohammed Morsi rallied on Sunday to demand his reinstatement, amid last ditch efforts for reconciliation ahead of a threatened crackdown on protests.

A large convoy of cars carrying pictures of the deposed president beeped their horns as they drove through a neighborhood in east Cairo.

U.N. Secretary General Ban Ki-moon on Friday appealed to Egyptians to avoid provocations and favor dialogue amid heightening tensions between supporters of deposed president Mohamed Morsi and the interim government.

Ban said he is "deeply concerned" by the political stalemate in Egypt, in a statement released by his spokesman on the occasion of the holiday marking the end of the holy Muslim fasting month of Ramadan.

Several Egyptian militants were killed in an air strike in Sinai on Friday as they prepared to launch a rocket into Israel, security sources and witnesses said.

The source of the strike was not immediately clear. Some sources spoke of an Israeli air strike conducted from Israeli air space and others credited the Egyptian military.

Islamist supporters of Egypt's deposed leader Mohammed Morsi planned new rallies on Friday as the interim premier suggested a crackdown on their protest camps was imminent.

Morsi supporters called for marches to begin after the Muslim Friday prayers at noon (around 1000 GMT) as the nation rested on the second day of the Eid al-Fitr holiday.

Iran's supreme leader Ayatollah Ali Khamenei on Friday warned the Palestinians against renewed peace talks with Israel, saying they would be "detrimental" to their cause.

The U.S.-mediated talks will force "the Palestinians to relinquish their rights," Khamenei told worshippers in Tehran University after Eid al-Fitr prayers marking the end of the holy month of Ramadan.

The airport in Israel's Red Sea resort of Eilat resumed flights on Thursday after a brief shutdown over unspecified security concerns, the Israeli military said.

"The airport is open after a new situation report," a spokeswoman told Agence France Presse, without further explanation.

Thousands of supporters of Egypt's ousted Islamist president Mohammed Morsi Thursday celebrated Eid al-Fitr, the end of the Muslim holy month of Ramadan, defying government calls for them to leave the streets.

However there was no immediate sign that the government was readying to carry out its threat made Wednesday to remove Islamist protest camps set up to demand Morsi's reinstatement following his ouster by the army on July 3.

U.S. President Barack Obama and Turkish Prime Minister Recep Tayyip Erdogan spoke by phone Wednesday to discuss developments in Syria and Egypt, the White House said.

During the course of the call, requested by Erdogan, the two "discussed the danger of foreign extremists in Syria and agreed on the importance of supporting a unified and inclusive" opposition, it said in a statement.