Iran's Foreign Ministry on Saturday appealed for the release of 48 of its citizens held hostage by rebels in Syria and threatened with execution one by one unless Syria's army withdraws from an area in Damascus province.

The statement, relayed by the official news agency IRNA, described the captives as "pilgrims."

Turkey hit back on Saturday against what it said was a fresh round of mortar fire from Syria, as monitors said rebels seized a Syrian border village after a fierce battle that left almost 30 dead.

Syria, for its part, said four Turks were among a convoy of "terrorists" killed in fighting in the heart of Aleppo, just hours after U.N. condemnation of deadly jihadist bombings in the commercial capital.

The head of Syria's main opposition coalition on Friday accused the Damascus regime of trying to spread the unrest in the country to the region, branding the deadly shelling of a Turkish town "a regime plan".

"This incident was a Syrian regime plan," Syrian National Council Chief Abdel Basset Sayda told reporters at a press conference in Istanbul, referring to the Syrian shelling that left five Turks dead in a nearby border town on Wednesday.

Turkey returned fire Friday after a new Syrian shell landed in on its territory close to their common border, NTV private news channel reported.

The Syrian shell landed in the Turkish town of Altinozu in Hatay province near the border, triggering an immediate response fire from Turkish forces, at around 1630 GMT.

Rebel fighters will execute dozens of Iranians they kidnapped in August unless Syria's army withdraws from the embattled Eastern Ghouta area of Damascus province, a rebel commander said on Friday.

"We gave the regime 48 hours starting yesterday to withdraw completely from the Eastern Ghouta area," Abul Wafa, commander of the rebels' Revolutionary Military Council in Damascus province, told Agence France Presse via the Internet.

The U.N. Security Council condemned Friday this week's "terrorist" attacks in the Syrian city of Aleppo that killed dozens of people and were claimed by a group affiliated with al-Qaida.

A statement agreed by the 15-nation council condemned the attacks "in the strongest terms" and expressed condolences to families of the victims "of these heinous acts."

Turkey's Prime Minister Recep Tayyip Erdogan again warned Syria on Friday it would pay a big price for further attacks, two days after a deadly cross-border shelling.

Erdogan reiterated that Turkey does not want war but is ready to act if threatened by the regime of President Bashar Assad, which has been at war with rebels since early last year.

A small group of Syrian Alawites, the same minority sect as President Bashar Assad, urged their community to join the anti-regime revolt in the country, in a statement sent to Agence France Presse on Friday.

"O Alawites all across Syria, enough is enough, so rise in unity against (Assad's) corrupt family whose only goals are treason, money and power," said a statement signed by a new movement calling itself "Free Alawites".

A top cleric on Friday urged Iranians to confront the "economic war" posed by Western sanctions and for authorities to cease internal bickering, days after protests erupted in Tehran over a collapse in Iran's currency.

"The pressure today imposed on us by the world arrogance (the United States) is full-fledged economic war," Ayatollah Ahmad Khatami said at the weekly Muslim prayers in Tehran broadcast by state media.

Tunisian police fired rubber bullets and tear gas to disperse hundreds of protesters in Sidi Bouzid who were demanding the governor's resignation, Agence France Presse reported.

Around 1,000 people gathered in the central Tunisian town, the birthplace of the uprising that toppled former dictator Zine El Abidine Ben Ali last year, accusing the governor of "incompetence" and calling for him to go.