Israeli, Greek and U.S. warships began a joint two-week Mediterranean naval exercise codenamed "Noble Dina" on Thursday, the Israeli military said.

"Noble Dina, one of the navy's scheduled annual exercises, is part of the security cooperation between the Israeli navy and foreign naval forces," a statement said. Israel's military sees it "as an opportunity for mutual learning and for strengthening of the cooperation with its allies."

Policemen across Egypt staged a strike on Thursday to demand the resignation of the interior minister, saying they no longer wanted to be used as a political tool, security officials said.

The discontent began weeks ago with isolated pockets of protest, but by Thursday police were on strike in areas of Cairo, Alexandria, the Nile Delta, the Suez Canal provinces, southern provinces and the Sinai peninsula.

Video footage posted on the Internet Thursday showed some of a group of 21 Filipino U.N. peacekeepers seized by Syrian rebels the previous day, with one of them saying they were safe and being cared for, as the U.N. said it was trying to negotiate the troops' release.

The Syrian Observatory for Human Rights posted the video which shows six uniformed members of the U.N. Disengagement Observer Force (UNDOF), and an officer who identifies himself as a member of the Filipino battalion of the U.N.

President Abdrabuh Mansour Hadi Thursday urged Yemen's army and security forces brass to be vigilant in case enemies of the state try to undermine a national dialogue set to begin later this month.

The army and security forces must be "vigilant" and on the lookout "for the enemies of security, stability and unity in Yemen," ahead of the March 18 national dialogue, the official Saba news agency reported him as saying.

Syria's opposition National Coalition meets next week in Istanbul to discuss the formation of an interim government and the selection of its head, a spokesman said on Thursday.

Tuesday's meeting will focus on "the question of a government and its chief," said Walid al-Bunni, while stressing that the discussions were not expected to lead to the designation of an opposition prime minister.

Two Britons were kidnapped on Thursday by Bedouin tribesmen in Egypt's Sinai but released soon afterwards following negotiations with security officials, police chief Magdi Moussa told Agence France Presse.

"They have been released and are heading back to their place of accommodation," Moussa said.

Syrian President Bashar Assad on Thursday hailed Turkish opposition to Prime Minister Recep Tayyip Erdogan's backing for the revolt that began in Syria nearly two years ago, in a statement seen by Agence France Presse.

The statement comes after Assad met a Turkish opposition delegation.

Medical charity Doctors Without Borders said Thursday that Syria's health system had collapsed after nearly two years of conflict and that foreign aid was falling fall short of what was needed to address the country's "humanitarian catastrophe".

The group, known by its French initials MSF, said in a report that more than a third of Syria's hospitals were no longer functioning and urged talks on allowing for the provision of humanitarian aid.

A court in Kuwait on Thursday sentenced two opposition activists to prison terms on charges of writing remarks on their Twitter accounts that were deemed offensive to the emir, a defense lawyer said.

Sager al-Hashash was given two years in jail with immediate effect while Nasser al-Deehani was handed a 20-month term but was asked to pay 200 dinars ($700) to suspend it, lawyer Khaled al-Humoud wrote on his own Twitter account.

A Palestinian who was seriously injured by a rubber bullet to the head during a protest which erupted after a prisoner died in Israeli custody died of his wounds on Thursday, medical officials said.

"Mohammed Asfour died this morning after being in hospital for a long time after he was injured during a demonstration," a spokesman for Tel Aviv's Ichilov hospital told AFP.