Former CIA chief and retired general David Petraeus wants the United States to consider working with some members of al-Nusra Front to tackle the Islamic State group in Syria, he said Tuesday.

In a statement to CNN, Petraeus said some members of al-Nusra Front might be persuaded to join the coalition battling the IS group.

General Security chief Maj. Gen. Abbas Ibrahim has said that the cell of Ahmed al-Asir has disintegrated after the arrest of the Salafist cleric at Beirut's airport last month.

In remarks to several local newspapers published on Tuesday, Ibrahim said al-Asir had been put under surveillance since the end of the battles between his supporters and the Lebanese army in Abra near the southern city of Sidon in June 2013.

Satellite images show the main temple in Syria's Palmyra has been flattened, confirming the worst fears for the ancient ruins held by the Islamic State group.

The destruction of the Temple of Bel sparked outrage and international headlines, precisely the reaction the jihadist group may have been seeking, experts said.

More than 10,000 Icelanders said Monday on Facebook they were ready to welcome Syrian refugees into their homes after the government said it would only let in a handful.

An Icelandic author and professor, Bryndis Bjorgvinsdottir, on Sunday urged fellow citizens to speak out on Facebook if they wanted Iceland, a country of around 330,000 inhabitants, to take in more Syrian refugees.

The verdict in the case of prominent Syrian human rights activist and dissident Mazen Darwish has been postponed until September 16, a lawyer close to the case said Monday.

Darwish and fellow activists Hani Zaitani and Hussein Ghreir were arrested in February 2012 and accused of "promoting terrorist acts".

Israel's Supreme Court on Monday confirmed a one-year jail sentence handed down to a Druze former MP for visiting Syria, an "enemy country."

Said Naffaa had appealed a September 2014 verdict sentencing him to 18 months for traveling to Syria and making contact with a "foreign agent."

The Islamic State group strung up four Iraqi Shiite fighters with chains and burned them alive, according to footage posted online, the latest gruesome execution video from the jihadists.

The victims -- identified as fighters in the pro-government Popular Mobilization forces from southern Iraq -- were suspended from a swingset-like metal structure by chains attached to their hands and feet, then set on fire.

The Islamic State group battled Syrian rebel forces in a Damascus neighborhood on Monday, bringing the jihadists closer than ever to the center of the capital, a monitoring group said.

IS militants fought street battles against Islamist rebels in Asali, part of the capital's southern Qadam district, after seizing two streets there over the weekend, the Syrian Observatory for Human Rights said.

A powerful blast in the ruins of Syria's ancient Palmyra raised fears Monday that the Islamic State group has damaged another of the Middle East's most treasured heritage sites.

Both Syria's antiquities chief and a monitor reported Sunday's explosion in the UNESCO World Heritage site, but there was conflicting information on the fate of its famed Temple of Bel.

Australia on Monday urged more European nations to begin air strikes against Islamic State group in Syria and Iraq as a way of tackling the escalating refugee crisis gripping the continent.

Foreign Minister Julie Bishop said jihadists were responsible for driving hundreds of thousands of migrants to Europe and a broadening of the coalition fighting them was necessary.