Egyptian army chief Abdel Fattah al-Sisi appeared to further set the stage this week for a presidential bid when he traveled to Russia, where President Vladimir Putin endorsed him as leader-in-waiting.

It was Sisi's first trip abroad since he overthrew Islamist president Mohammed Morsi in July, setting off months of deadly unrest.

Russia and Egypt are nearing a $3-billion arms purchase agreement that will be financed by Saudi Arabia and the United Arab Emirates, a Moscow newspaper reported on Friday.

The two sides have already either "initialed or signed" contracts for Egypt's purchase of Mig-29 fighters, air and coastal defense systems, Mi-35 attack helicopters and smaller arms, the Vedomosti daily quoted two Russian government sources as saying.

The United States scolded Russian President Vladimir Putin on Thursday for endorsing Egyptian military chief Abdel Fattah al-Sisi in the key U.S. ally's presidential polls.

Washington also assured that a warming of relations between Cairo and Moscow wouldn't harm the "historic" ties shared between Egypt and the United States, which have soured in recent months.

Russian President Vladimir Putin on Thursday endorsed Egyptian army chief Abdel Fattah al-Sisi's undeclared bid to head the strife-torn North African nation as the two leaders negotiated a massive Moscow weapons deal.

Sisi came to Moscow with Egyptian Foreign Minister Nabil Fahmy for talks aimed at securing Russian assistance -- stagnant since the late Soviet era -- that could replace subsiding support from Cairo's more recent ally Washington.

An Egyptian court overturned Wednesday the conviction of a policeman accused of killing protesters in Cairo during the 2011 uprising against Hosni Mubarak, drawing charges of judicial double standards.

The ruling comes as the military-installed authorities have been waging a deadly crackdown on supporters of deposed Islamist president Mohammed Morsi, put on trial many Islamist leaders, including Morsi himself, and arrested thousands of Islamists.

Army chief Abdel Fattah al-Sisi, who is likely to become Egypt's next president, headed to Russia accompanied by Foreign Minister Nabil Fahmy on Wednesday to discuss bilateral cooperation, the army said.

Field Marshal Sisi, who is also Egypt's defense minister and deputy prime minister, and Fahmy would hold "2+2" talks with their Russian counterparts, army spokesman Colonel Ahmed Aly said in a statement.

Gunmen shot dead three policemen near the Suez canal city of Ismailia and seized their weapons, bringing to five the number of policemen killed in 24 hours in Egypt.

Attacks on security force personnel have surged since the army ousted Islamist president Mohamed Morsi in July and the military-installed authorities launched a deadly crackdown on supporters of the deposed leader.

Egyptian and Sudanese security officers have colluded with traffickers accused of holding Eritrean migrants for ransom and torturing them, Human Rights Watch said Tuesday.

Victims accused the traffickers of raping both women and men, administering electric shocks and burning genitalia and other body parts with hot irons, boiling water and molten plastic, the New York-based rights group said.

Suspected militants blew up a gas pipeline in Egypt's Sinai peninsula on Tuesday and gunmen shot dead a policeman in the Suez canal city of Ismailia, security officials said.

Attacks in the Sinai and violence targeting soldiers and policemen across Egypt have surged since the military's overthrow of Islamist president Mohamed Morsi in July.

Al-Jazeera journalists accused of backing Egypt's blacklisted Muslim Brotherhood are to go on trial on February 20, judicial sources said on Monday.

Since president Mohammed Morsi was ousted by the military in July, Egypt's interim government has been incensed by Al-Jazeera television's coverage of a deadly crackdown against the Brotherhood to which the deposed Islamist belongs.