A U.N.-Arab League peace plan for Syria has only a three percent chance of working, the emir of Qatar said on a visit to Rome Monday, as a U.N.-backed ceasefire was marred by ongoing violence.

Sheikh Hamad bin Khalifa al-Thani told a press conference that the chances for success "are no higher than three percent", and that the Syrian people should not be supported through peaceful means but "with arms".

A German shipping firm on Monday dismissed reports one of its vessels was carrying Iranian arms bound for Syria in violation of EU sanctions against the regime of President Bashar al-Assad.

Respected news weekly Der Spiegel reported at the weekend that the ship, the Atlantic Cruiser, owned by German firm Bockstiegel but chartered by a Ukrainian firm, had been stopped on the high seas with Iranian weapons on board.

The United States warned Monday that heightened violence in Syria threatens the sending of a full U.N. ceasefire observer mission as it voiced fear that a ceasefire is "eroding."

The U.S. ambassador to the United Nations, Susan Rice, said new attacks by government forces "call into question the wisdom and viability" of sending the full 200 international monitors.

Israeli authorities were on Monday holding 47 foreigners pending deportation, out of 79 barred from entering the Jewish state because of their links to a pro-Palestinian campaign, an official said.

"There are 47 people still awaiting deportation, including 37 French nationals, eight Britons, an Italian and a Canadian," immigration official Sabine Haddad told Agence France Presse.

The U.N.-appointed panel tasked with investigating rights abuses in Syria on Monday voiced concern over reports of post-ceasefire shelling by government forces.

The Commission of Inquiry on Syria said it had received accounts that the Khaldieh neighborhood and other districts of Homs had been bombarded since Thursday.

The United Arab Emirates warned on Monday that a Gulf islands dispute with Iran threatens "international security."

The UAE has summoned Iran's ambassador to Abu Dhabi to denounce a visit last week by President Mahmoud Ahmadinejad to one of the three disputed islands, the official state news agency said on Monday.

Syrian tribes opposed to the embattled regime of Bashar al-Assad said Monday they would join forces in an "Assembly of Tribes," Syrian opposition members and media reported.

"Today we proclaim, as children of all tribes, an Assembly of Tribes," opposition Syrian National Council (SNC) member Mahmut al-Maslat said in a statement read out on behalf of the assembly.

Jobless protesters in an industrial suburb of Tunis threw petrol bombs and stones at police trying to break up their sit-in at a cargo handling company, the interior ministry said Monday.

The protest was sparked by the publication at the weekend of successful applicants for job openings at a stevedoring company near the port of Rades, 15 kilometers (nine miles) south of Tunis, the ministry said.

Tehran on Monday warned Arab states in the Gulf that things could become "very complicated" if they do not act cautiously over a simmering islands dispute between Iran and the United Arab Emirates.

Foreign Minister Ali Akbar Salehi made the declaration to Iran's ISNA news agency on the eve of talks in Doha between the Gulf Cooperation Council (GCC) states over three tiny islands in the Gulf and claimed by both Iran and the UAE.

Libyan leader Mustafa Abdel Jalil expressed confidence Monday that Algeria would not shelter anyone who poses a threat to his country, in a reference to Moammar Gadhafi’s family members who were granted asylum by Algiers.

"We appreciate the humanitarian position of Algeria for hosting the families, including women and children, but we are convinced that it would not shelter those who represent a threat for Libya's security," said Abdel Jalil after meeting Algeria's President Abdelaziz Bouteflika.