A top Israeli official vowed Friday to "prevent Iran from acting" if it seeks to use a nuclear weapon, amid growing impatience over Tehran's refusal to come clean on its nuclear program.

Israeli Deputy Foreign Minister Danny Ayalon warned on a visit to Argentina that a nuclear-armed Iran would have "ramifications throughout the world" and allow Tehran to "achieve hegemony in the Middle East.

Two huge bomb blasts killed at least 27 people in Syria's capital on Saturday, sparking anger at Riyadh and Doha, as special envoy Kofi Annan warned of regional fallout from the year-long bloodshed.

State television said the early morning "terrorist" attacks, apparently car bombings timed minutes apart, had targeted police headquarters in the Duwar al-Jamarek area and air force intelligence offices in al-Qasaa district.

Militants in the Gaza Strip fired two rockets into southern Israel on Friday, officials said, as a fledgling truce in and around the Palestinian territory firmed up.

"One rocket hit an empty field in the Eshkol region, causing no damage or injuries," police spokeswoman Luba Samri told Agence France Presse.

Clashes pitting backers and opponents of federalism in the eastern Libyan city of Benghazi killed one person and wounded at least five on Friday, a medical official said.

"One person was killed and at least five others were wounded," Basma Mohammed told Agence France Presse.

Special envoy Kofi Annan warned of an "escalation" of the Syria conflict into the rest of the Middle East unless it is carefully handled as he called on the U.N. Security Council to unite to put pressure on President Bashar al-Assad.

Annan gave his warning as Turkey told its nationals to leave Syria where thousands took part in new protests against the government. Activists said at least another 15 people were killed.

A Palestinian protester was bitten by an Israeli army attack dog during a protest in the West Bank village Kafr Qaddum west of Nablus on Friday, an Agence France Presse correspondent said.

An Israeli military spokeswoman acknowledged to AFP that a demonstrator was "lightly wounded" by the dog.

Foreign affairs chief Catherine Ashton said Friday she will maintain the European Union's diplomatic presence in Damascus regardless of decisions taken by member states on their own needs.

"The issue of diplomatic representation in the country is of course under constant review by the member states, but there is no common line at this time," said Ashton's spokesman Michael Mann.

Foreign ministers from Tunisia, Egypt and Libya, meeting in Tunis said Friday the Syrian crisis should be resolved in an "Arab framework" and opposed foreign military intervention in the country.

"We are all against military intervention in Syria, and we want the problem to be resolved in an Arab framework," Tunisian Foreign Minister Rafik Abdessalem said after meeting with his Egyptian and Libyan counterparts, Mohamed Amr and Ashour bin Khayyal.

The United States said Friday it is concerned about Iranian cargo flights over Iraq to Syria, saying it has warned Iraq they might contain arms that could be used by Damascus to crush protests.

"Without getting into intelligence matters, we are concerned about the overflight of Iraq by Iranian cargo flights headed to Syria," State Department spokeswoman Victoria Nuland told reporters.

French Foreign Minister Alain Juppe urged the Syrian opposition to stop "tearing itself apart" in an interview published on Friday, in which he also opposed providing Syrian rebels with arms.

"There are some opponents whose attitudes are seriously weakening the opposition -- as long as they continue to tear themselves apart and fight amongst themselves," Juppe said in an interview with French newspaper Le Monde.