U.N. Secretary General Ban Ki-moon said on Tuesday he feared that the militarization of the conflict in Syria could turn the country into a "regional battleground."

"We are deeply concerned about the continued militarization of the conflict, horrendous violations of human rights and the risk of Syria turning into a regional battleground as the violence intensifies," Ban told reporters during a visit to Cairo.

Security guards at the U.S. embassy in Tel Aviv on Tuesday fired shots at a man who attacked them with a knife and an axe, an Israeli police spokeswoman said, indicating the attacker had been apprehended.

"A suspect came to the U.S. embassy at 11:00 am (0900 GMT) with a knife and an axe and attacked a security guard," spokeswoman Luba Samri told AFP, saying the guard was injured in the leg, prompting his colleagues to open fire.

Turkish Foreign Minister Ahmet Davutoglu said on Tuesday that NATO member Ankara would formally ask the alliance for Patriot missiles to protect its border with conflict-wracked Syria.

"(Patriots) are a precautionary measure, for defense in particular," Davutoglu told reporters before he left Ankara for Gaza. "We will submit the formal request as soon as possible."

Two mortars hit the Syrian Ministry of Information building in Damascus on Tuesday morning, leaving no casualties and causing minimal damage, state news agency SANA said.

The building is also home to the newspaper of the Baath Party, which holds a monopoly on power in the country, and is located on the Mazzeh highway in the west of the city.

The Kuwaiti opposition has announced it will stage a major demonstration on the eve of the December 1 parliamentary election as a finale to its nationwide campaign to urge a boycott of the disputed polls.

The Islamist, nationalist and liberal opposition all say the poll boycott is in protest at the government's unilateral amendment of the electoral law, which it says breaches the constitution.

China backed calls Tuesday for an immediate ceasefire in the Gaza conflict and urged the U.N. Security Council and the international community to bring peace to the region.

A statement by China's Foreign Ministry came as senior Israeli ministers decided overnight to hold off from launching a ground invasion of the Gaza Strip to give Egyptian-led truce efforts a chance to work.

Secretary of State Hillary Clinton will leave Asia on Tuesday to visit Israel, Egypt and Ramallah, stepping up U.S. efforts to avoid a worsening of the Gaza crisis, an official said.

Clinton will meet Israeli Prime Minister Benjamin Netanyahu and discuss the crisis with Egyptian and Palestinian leaders, after leaving President Barack Obama's trip to Southeast Asia, said senior Obama aide Ben Rhodes.

At least 20 Palestinians were killed on Tuesday as Israeli air strikes rocked the Gaza Strip, medics in the Hamas-ruled territory said, as a rocket fired by Palestinian militants exploded near Jerusalem.

Two cameramen from Hamas-owned Al-Aqsa TV were among six people killed in a series of Israeli air raids on Gaza City and the north, a Hamas spokesman said.

U.N. chief Ban Ki-moon on Tuesday urged all sides to the Gaza conflict to immediately cease their fire, warning at a news conference in Cairo that an escalation will endanger the whole region.

"All sides must halt fire immediately," Ban said, as an Israeli military operation against rocket-firing militants in Gaza entered a seventh day, with 116 Palestinians and three Israelis killed.

Israel's President Shimon Peres accused Iran Monday of encouraging the Palestinians to continue rocket attacks on Israel rather than negotiating a ceasefire, saying "they are out of their mind."

At the same time, Peres praised Egypt's President Mohammed Morsi for the constructive role he has played in the intensifying crisis.