Lebanon is acting in a "blatantly discriminatory" manner by denying access to Palestinians fleeing the conflict in neighboring Syria, Amnesty International said in a report on Tuesday.

The watchdog said Lebanon has imposed increasingly onerous entry requirements at the border with Syria and that there was evidence it is trying to prevent Palestinian refugees from entering via Beirut airport.

The jihadist Islamic State seized control of the key Syrian border town of al-Bukamal on Tuesday after a fierce three-day battle with rival fighters, a monitor said.

A spokesman for rebels fighting IS as well as President Bashar Assad's regime said the jihadists took the town after pouring in reinforcements from neighboring Iraq, where they have overrun chunks of territory in a swift offensive.

Iraq's new parliament broke up in chaos Tuesday, with lawmakers walking out and making threats despite global calls for the formation of a government needed to face a Sunni militant onslaught.

After a break called to calm soaring tempers, so many Sunni and Kurdish deputies stayed away that the quorum was lost, so a speaker could not be elected as was constitutionally required, and the session ended in disarray.

Jihadists from the Islamic State must free some 133 Kurdish schoolboys kidnapped in Syria a month ago, Human Rights Watch said on Tuesday.

The group, formerly known as the Islamic State of Iraq and the Levant, kidnapped some 153 schoolchildren on May 29.

Russia urged U.N. Security Council members Monday to back a draft statement to bar crude oil sales by "terrorist groups" in Syria, including as the Islamic State of Iraq and the Levant

The text voices the council's concern at oil fields in Syria being seized by militants, and cites ISIL and al-Nusra Front.

The United States said Monday the declaration by Sunni militants of an "Islamic caliphate" on territory they have seized in Iraq and Syria has "no meaning."

"We have seen these types of words from ISIL before," State Department spokeswoman Jen Psaki told reporters, referring to militants of the Islamic State of Iraq and the Levant. 

Activists in Raqa, a stronghold of the Islamic State (IS), said Monday the jihadists have locked down the Syrian city and are shipping in new weapons, including missiles from Iraq.

"All roads leading in and out of Raqa city have been closed. Nobody can enter or leave Raqa at all right now," said Hadi Salameh, speaking to Agence France Presse via the Internet.

Three booby-trapped cars were discovered in Syria's Qalamoun plains on the border with Lebanon, among them two with Lebanese license plates, Syria's state TV announced on Monday afternoon.

The cars were found in Qalamoun's Wadi al-Hossayn region, the TV network noted.

French Foreign Minister Laurent Fabius said Monday that jihadists spearheading a militant offensive in Iraq have sold oil from captured areas to the regime of Syrian President Bashar Assad.

Fabius said the sale was evidence of the "confusing" nature of the escalating conflict in the Middle East in which Assad and the jihadists are in theory on opposing sides.

Rebel mortar shells pounded Syria's northwestern city of Idlib on Monday, killing 14 people, state television said, a day after 27 people died in regime air raids on a nearby opposition-held area.

"Fourteen people were killed and more than 50 others wounded by mortars launched by the terrorists (rebels) on several areas of Idlib city," said the state channel.