Iran "strongly" denies that 48 of its citizens taken hostage in Syria at the weekend are Revolutionary Guards, as claimed by their rebel captors, according to the state television website on Monday.

"We strongly reject the claims of some media that the kidnapped pilgrims are members of Iran's Revolutionary Guards," Amir Abdollahian, a deputy foreign minister in charge of Arab affairs, was quoted by the IRIB broadcaster as telling Iran's al-Alam Arabic-language network.

Syrian regime forces shelled several areas of the northern city of Aleppo on Monday morning, and shooting was also reported in other neighborhoods of the embattled commercial capital, monitors said.

Clashes in the rebel-held district of Salaheddin killed a rebel commander, the Britain-based Syrian Observatory for Human Rights said.

Three prominent U.S. senators called late Sunday for direct U.S. military aid to Syrian rebels, including use of air power to protect rebel-controlled areas in the country.

The senators -- John McCain, Joseph Lieberman and Lindsey Graham - said in an op-ed piece in The Washington Post they were aware of the risks associated with deepening U.S. involvement in the conflict in Syria.

Three Syrian intelligence officers have defected from the Damascus regime and sought refuge in neighboring Jordan, a spokesman for the rebel Free Syrian Army said on Sunday.

"Colonel Yaarab al-Sharaa, his brother Mohammed Kanaan al-Sharaa and Colonel Yasser Ali Hajj, who worked in political intelligence in Damascus, have defected and are in Jordan," Kassem Saadeddine told Agence France Presse.

Abu Ibrahim, the head of the armed group that abducted the 11 Lebanese Shiite pilgrims in Syria, refuses to negotiate with Lebanon’s General Security chief Maj. Gen. Abbas Ibrahim over their release, LBCI television reported on Sunday.

Ali Aqil Khalil, the ambassador of the International Organization for Human Rights to Lebanon, told LBCI that he telephoned Abu Ibrahim who said that he rejects General Ibrahim as a possible negotiator due to the General Security’s latest deportation of 14 Syrians to their strife-torn country.

A British photographer who was held hostage in Syria for a week said on Sunday that his captors were international jihadists who included several Britons.

Freelance photographer John Cantile and his Dutch colleague Jeroen Oerlemans were kidnapped in northern Syria on July 19 and freed a week later.

Some 600 Palestinian families have arrived in Lebanon from Syria, most of them fleeing violence at the Yarmuk refugee camp in Damascus, a Palestinian official in Lebanon said on Sunday.

"Some 600 Palestinian families have arrived in Lebanon's Palestinian refugee camps in the past three days," said Marwan Abdel Aal of the Lebanese branch of the Popular Front for the Liberation of Palestine.

Germany's defense minister again ruled out military intervention in Syria Sunday, warning it should not be considered a knee-jerk response to the failure of diplomatic efforts to end the bloodshed.

Thomas de Maiziere told the Welt am Sonntag newspaper that Kofi Annan's decision to quit as international peace envoy to Syria did not change Germany's stance on the sending of troops into the nearly 17-month conflict.

General Mohammed Ahmed Faris, a military aviator who became the first Syrian in space, fled to Turkey on Sunday after defecting from President Bashar Assad's regime, the Anatolia news agency reported.

Before crossing into Turkey, Faris visited the headquarters of the Free Syrian Army in his home town Aleppo in a show of solidarity with rebel forces battling Assad's troops in Syria's biggest city, it said.

A Syrian opposition source dismissed Sunday as fake an online video of the 48 Iranians kidnapped in Damascus, saying it was designed to cover-up the responsibility of hardline Sunni Islamist group Jundallah.

The source said that the faction -- which has no relation with the Sunni rebel group of the same name active in southeastern Iran -- was one of an array of Sunni Islamist factions that have proliferated in Syria in recent months.