U.S. Defense Secretary Chuck Hagel landed in Egypt on Wednesday as part of a Middle East tour designed to bolster America's alliances amid growing concern over the fallout from Syria's roiling civil war.

In his first trip to the Middle East as Pentagon chief, Hagel is promoting longstanding U.S. military ties with traditional allies -- including Israel and Saudi Arabia -- as a way of countering Iran and deterring Islamist militants.

An adviser to President Mohamed Morsi has submitted his resignation in protest at the running of the state and the "failure" of the government, Egyptian media announced on Tuesday.

"Mohamed Fuad Gadallah, presidential adviser on judicial affairs, is resigning," the public television channel Nile News said.

The United States has withdrawn a demand that the United Nations start human rights investigations in disputed Western Sahara following furious lobbying by Morocco, diplomats said Tuesday.

Morocco, which has occupied Western Sahara since the 1970s, had condemned a U.S. move to put the demand in a U.N. Security Council resolution on the U.N. peacekeeping mission in the North African territory to be voted on Thursday.

Bomb attacks on Sunni mosques in Iraq killed 13 people and wounded dozens of other people on Tuesday, security and medical officials said.

Two rounds of mortar fire hit a mosque in Muqdadiyah, northeast of Baghdad, killing nine people and wounding 25, police and a doctor said, revising an earlier casualty toll.

U.S. Secretary of State John Kerry said Israeli Prime Minister Benjamin Netanyahu had not been able to confirm to him on Tuesday that the Syrian regime had used chemical weapons against rebels.

"I think it is fair to say (the prime minister) was not in a position to confirm that in the conversation," Kerry said, explaining that he had telephoned Netanyahu following reports of their use.

Jordan's parliament on Tuesday passed a vote of confidence in Prime Minister Abdullah Nsur who faces the challenge of dealing with fallout from the war in neighboring Syria.

The vote was passed 83-65 in the lower house.

U.S. Secretary of State John Kerry and his Russian counterpart Sergei Lavrov discussed the deteriorating situation in Syria on Tuesday, stressing the need for a political solution, a U.S. official said.

The two have met several times since Kerry took office earlier this year, with Syria a growing cause of international concern amid fears the bloody conflict could spill over into an already volatile region.

An association of Middle Eastern Christians on Tuesday said that two Orthodox bishops reportedly kidnapped by rebels in northern Syria have been released, in a statement citing Syrian sources.

The French "Oeuvre d'Orient" association said that the two -- Bishop Yohanna Ibrahim and Bishop Boulos Yaziji, who were seized on Monday -- were already at Saint Elias cathedral in Aleppo.

Armed protesters killed six Iraqi soldiers and kidnapped a seventh on Tuesday near Ramadi, west of Baghdad, a police officer said.

The protesters also burned two armored personnel carriers and were holding the kidnapped soldier at the site of their sit-in on the highway near Ramadi, First Lieutenant Ibrahim Faraj said.

U.S. Defense Secretary Chuck Hagel arrived in Riyadh Tuesday to seal a major arms deal that will provide the Saudi kingdom with sophisticated missiles for its American-made fighter jets.

Hagel flew in from Jordan after a three-day visit to Israel in his first tour of the region since he took office two months ago.