The U.S. government has been quietly trying to block arms and oil shipments from Iran to Syria in a bid to accelerate the fall of Syrian President Bashar Assad, The Wall Street Journal reported late Sunday.

Citing unnamed U.S. officials, the newspaper said the efforts are aimed at getting Iraq to close its airspace to flights between Iran and Syria that U.S. intelligence believes are carrying arms for Syrian pro-government forces.

The situation in Syria is "calm," requiring no repatriation of Iranian citizens there, Iranian Foreign Minister Ali Akbar Salehi said on Sunday, according to the official news agency IRNA.

"Syria is calm and Iranian nationals who are there have no problem and there is no need to conduct any special action" for them, Salehi was quoted as saying.

A YouTube video uploaded on Sunday showed Hussam Hussam -- who has claimed to be a witness in the 2005 assassination of ex-PM Rafik Hariri – in the custody of a group of Syrian rebels.

The group said it was part of the “brigades” that “stormed” the Syrian capital Damascus.

A Syrian rebel commander on Sunday said that 11 Lebanese pilgrims abducted in Syria on May 22 were in “good health” but stressed that they will only be released “after the ouster” of Syrian President Bashar Assad, according to media reports.

Al-Jazeera television aired Tuesday a video it said it received from the abductors of 11 pilgrims.

Israel will not tolerate the transfer of advanced weapons to Hizbullah, Defense Minister Ehud Barak said on Sunday, as fears grew about the future of Syria's suspected chemical arsenal.

"The State of Israel cannot accept the transfer of advanced weapons systems from Syria to Lebanon," he said in remarks relayed by his office.

Turkish police fired tear gas on stone-throwing Syrian refugees who were protesting Sunday at the lack of food and water at camps on the border with their conflict-ravaged homeland.

A Turkish official said demonstrations erupted at two of the 10 camps set up along the border which are sheltering about 40,000 Syrians who have fled the escalating violence at home.

UNRWA on Sunday expressed concern over the fate of some half a million Palestinian refugees living in war-torn Syria, particularly those residing in the Yarmouk neighborhood of Damascus.

"UNRWA views with increasingly grave concern the situation in Syria, particularly as regards the implications for the stability and protection of 500,000 Palestine refugees across the country," the agency said.

Turkey sent batteries of ground-to-air missiles to the border with Syria on Sunday, media reports said, boosting its firepower as rebels in Syria seized several border posts.

As fighting raged in Damascus and Aleppo, rebels were said to have taken control of three crossing points on the border with Turkey, which is sheltering thousands of Syrians who have fled the conflict at home.

Syrian President Bashar Assad on Sunday received his newly appointed army chief-of-staff General Ali Ayyoub, state television reported.

"President Assad met chief-of-staff General Ali Ayyoub and gave him his instructions," the broadcaster reported.

Syrian rebels' seizure of crossings along the frontier with Iraq marks a blow to Bashar Assad's regime, but has also divided communities that have long straddled the border.

Of the three main crossings between Syria and Iraq, rebels have maintained control over the al-Bukamal border point since Thursday evening, and briefly held the Yarabiyah crossing along the northern part of the two countries' frontier.