Several hundred people marched in central London on Saturday to protest Britain's involvement in U.S.-led air strikes against Islamic State (IS) group targets in Iraq.

Demonstrators chanted slogans including "Hands off the Middle East, no justice, no peace" and held up placards with slogans such as "Stop bombing Iraq."

Justice Minister Ashraf Rifi on Saturday stressed that the case of the captive troops is “the top priority in Lebanon,” describing their abduction as a “black point in the course of the Syrian revolution.”

“The case of the captives is the top priority in Lebanon, at the level of the government, military and security institutions, and all political sectors,” Rifi said as he visited the Qalamun highway to express solidarity with families of captive troops, who have been staging a sit-in there for days now.

The U.N. Security Council has strongly condemned the "heinous and cowardly" murder of British hostage Alan Henning, shown in a video with an Islamic State fighter. 

In a unanimous statement issued late Friday, the 15-member council said the "continued acts of barbarism perpetrated by ISIL do not intimidate them, but rather stiffen their resolve" to counter the jihadists.

Turkey warned on Saturday it would not hesitate to strike back at Islamic State jihadists if they attacked Turkish troops stationed at Ankara's exclave inside Syria.

"We will absolutely not hesitate to respond if something happens there," President Recep Tayyip Erdogan told reporters in Istanbul, referring to the tomb of Suleyman Shah, the grandfather of the founder of the Ottoman dynasty Osman I.

At least 35 jihadists from the Islamic State group were killed in air strikes by a U.S.-led coalition overnight in northern and northeastern Syria, a monitor said Saturday.

The Syrian Observatory for Human Rights said 30 jihadists were killed around the town of Shadadi in northeastern Hasakeh, and another five outside the embattled town of Kobane, on the border with Turkey in northern Aleppo province.

Syria's President Bashar Assad made a rare public appearance on Saturday, attending prayers on the Muslim Eid al-Adha holiday at a mosque in Damascus, state media said.

State media and Assad's official Twitter feed posted photos of the embattled president praying alongside the country's top cleric and members of his government.

Outgoing Israeli army chief of staff Lt. Gen. Benny Gantz was optimistic that Hizbullah would not launch an attack on the Jewish state soon but did not rule out a future war.

“We don’t expect war to be initiated against us in the coming year, but there could be a deterioration as a result of specific events” as occurred in the Gaza Strip, Gantz said in interviews published in eight newspapers in the past days and over the weekend.

Kurdish fighters backed by U.S.-led air strikes held back jihadists attacking a Syrian border town Saturday, following an international outcry at the murder of a British hostage by the Islamic State group.

Dozens of militants with the Islamic State (IS) organization were reported dead in the latest American-led coalition air raids.

Dutch F-16 fighter bombers could be in action over Iraq by this weekend in the campaign against the Islamic State group (IS), Defense Minister Jeanine Hennis-Plasschaert said on Friday.

"I would like to inform you that Dutch F-16s could commence operations this weekend in the fight against the IS," she said in a letter to the Dutch parliament.

The father of British photojournalist John Cantlie on Friday urged his Islamic State jihadist captors to release him to those "he loves and who love him", saying he was only in Syria to help.

Speaking from a hospital bed with the aid of an electrolarynx, Paul Cantlie revealed his joy at seeing a video of his son, who went missing in Syria in November 2012, but also the ongoing pain felt over his detention.