Syrian Ambassador to the United Arab Emirates Abdul-Latif al-Dabbagh has defected, al-Jazeera TV reported Wednesday.

The Doha based television said that Dabbagh defected but it did not say where he was.

Half of the members of the United Nations observer mission in Syria have left the country, two mission members told Agence France Presse on Wednesday.

"One hundred and fifty observers left Syria on Tuesday evening and Wednesday and they will not come back," one observer told AFP.

Russia condemned on Wednesday a new round of EU sanctions against Syria over the prolonged conflict with the opposition as amounting to an air and sea "blockade" of its Soviet-era ally.

"Essentially, the measures taken by the European Union can be considered a declaration of a sea and air blockade of Syria," the Russian foreign ministry said in a statement.

Al-Qaida's Iraq front group claimed a wave of attacks that killed 113 people on Monday in Iraq's deadliest day in two and a half years, saying it marked the launch of a new campaign promised by its leader.

"As part of the new military campaign aimed at recovering territory given up by the Islamic State of Iraq (ISI), the war ministry has sent its sons and the mujahedeen on a sacred offensive during the month of Ramadan," the group said in a statement posted on jihadist website Honein.

Turkey will close its border crossings with neighboring strife-torn Syria on Wednesday until further notice, a Turkish official told Agence France Presse.

"We have taken such a measure for our citizens for security reasons," said the official. "This is an open-ended measure and the reopening depends on the developments on the ground."

The Syrian army and rebels deployed more forces in and around Aleppo on Wednesday as a "decisive" battle for control of the country's second city raged, activists and regime sources said.

"Hundreds of rebels from all over the north of Syria are arriving in Aleppo, which appears to have become the decisive battle," a journalist for a Syrian newspaper working in the city told Agence France Presse.

Palestinian militants in the Gaza Strip fired a rocket toward the southern Israeli city of Ashkelon on Tuesday evening but it was intercepted by the Iron Dome air defense system, the military told Agence France Presse.

On Friday two rockets slammed into open ground in Israel's south, without causing casualties or damage.

The head of the Syrian embassy in Cyprus, Lamia al-Hariri, has defected to Qatar, pan-Arab satellite television networks reported on Tuesday.

Al-Jazeera television said in a brief report that Hariri, the charge d'affaires, had "announced her defection in Cyprus," while Al-Arabiya said she had arrived in the Gulf state of Qatar.

A Russian naval flotilla of warships destined for the Syrian port of Tartus has entered the Mediterranean, Russia's defense ministry said Tuesday.

"The Russian ships today passed the Strait of Gibraltar and entered the Mediterranean at 1200 GMT," said a defense ministry spokesman, quoted by Itar-Tass agency.

The United States is stepping up support for the Syrian opposition amid signs events in the 16-month uprising are moving faster on the ground, Secretary of State Hillary Clinton said Tuesday.

After failing to win a U.N. Security Council resolution on Syria after Russia and China imposed their vetoes, the United States is working outside the council to send "a clear message of support for the opposition," she said.