Egyptian Islamist sheikh Hazem Abu Ismail kicked off his candidacy for the presidency on Friday with a large motorcade that headed to the electoral committee headquarters in Cairo.

Witnesses said dozens of vehicles packed with the ultra-conservative's supporters left a mosque with the statutory 30,000 endorsements from citizens required to register as a candidate.

The United States hit Syria's defense minister and two other senior military figures with sanctions Friday, ramping pressure on Bashar al-Assad's regime as U.N. efforts failed to halt violence.

The Treasury Department announced measures against Dawoud Rajiha as well as the army's deputy chief of staff and the head of presidential security.

More than 15,000 people in Jordan, including opposition Islamists and trade unionists, held a peaceful sit-in near the border with Israel on Friday to mark Land Day.

Waving Jordanian and Palestinian flags, the demonstrators carried banners reading: "Freedom for Jerusalem and freedom for Palestine," and "Jerusalem, here we come," as they gathered in Kafrein, some 10 kilometers (six miles) from the border crossing and barely a kilometer and a half (a mile) from the frontier.

Amnesty on Friday urged Bahrain to immediately release a rights activist jailed for his role in anti-regime protests, warning his life is at risk after a hunger strike of more than seven weeks.

Abdulhadi al-Khawaja had lost 16 kilograms (35 pounds) since beginning a hunger strike 50 days ago, the London-based human rights watchdog said, citing the activist's lawyer.

A 20-year-old man was killed and another 51 people injured by Israeli fire on Friday, as thousands rallied across the West Bank and Gaza to mark Land Day, medical sources said.

Demonstrations also took place in annexed east Jerusalem and across Israel, as well as in Jordan, southern Lebanon and Syria to mark the annual event that commemorates the deaths of six Arab Israelis at the hands of Israeli forces during protests against land confiscation in 1976.

Egyptian liberal groups said on Friday that they were back to square one in a struggle with Islamists over the drafting of a new constitution a day after most parties agreed on a compromise.

China said Friday that rebels fighting in Syria had to commit to talks and stop attacks they have been carrying out, mirroring demands from embattled Syrian President Bashar Assad.

A peace plan put forward by U.N. envoy Kofi Annan includes a call for a full cease-fire, but Assad's condition that there be an express promise from the opposition to stop attacks could complicate Annan's attempts to bring an end to more than a year of violence that the U.N. says has killed more than 9,000 people.

Deadly clashes raged and anti-regime protesters rallied across Syria on Friday to denounce the Arab League’s inaction in the face of a bloody crackdown on dissent after the annual Arab Summit only urged dialogue to resolve the crisis, as U.N.-Arab League envoy Kofi Annan urged the regime to immediately implement a ceasefire.

The Local Coordination Committees, the main activist group spurring protests on the ground, said security forces killed 45 people across the country: nine in Daraa, 14 in Deir al-Zour, three in Aleppo, 12 in Homs, four in Idlib, two in Damascus and one in Hama.

U.S. Secretary of State Hillary Clinton arrived in Riyadh Friday for talks with Saudi leaders as she kicked off a two-country tour aimed at raising pressure on the Syrian regime, the U.S. embassy there said.

"Mrs. Clinton has arrived in Riyadh for talks with senior Saudi officials," an embassy spokesman said.

Syrian activists called for mass protests on Friday to denounce Arab countries for "abandoning" them as Syrian forces shelled rebel bastions in the central city of Homs and launched assaults in northwestern Idlib province.

"The Muslims and the Arabs have abandoned us ... but God is with us ... and our determination will carry us to victory," said a statement posted on the Syrian Revolution 2011 Facebook page, urging nationwide street demonstrations after the weekly Friday prayers.