Islamic State militants have released a video showing 25 men being executed by what appear to be teenagers in an ancient amphitheater in the Syrian city of Palmyra.
The video, uploaded to social media Saturday, purports to show IS militants leading a group of what are said to be Syrian government soldiers from the notorious Palmyra prison to the amphitheater, where they are then shot.
Stills from the video showed the killers to be young males — some as young as 13 or 14 — wearing desert camouflage and brown bandannas.
IS has reportedly carried out more than 200 executions in and around Palmyra since it captured the city in May.
Also Saturday, Syrian troops backed by Lebanese Hezbollah militia fighters began a major offensive to retake a rebel-held mountain resort while opposition fighters retaliated by shelling the capital, Damascus.
Footage released by Hezbollah's al-Manar television station showed large plumes of fire rising from Zabadani, located northwest of the Syrian capital near the border with Lebanon.
Al-Manar reported Hezbollah fighters and Syrian troops, under the cover of airstrikes, are attacking from several directions and that rebels are isolated inside Zabadani.
The city is close to the Beirut-Damascus highway that links Syria and Lebanon. Capturing it would be a strategic gain for Syrian President Bashar al-Assad's government.
Zabadani has been held by rebels since shortly after Syria's crisis began in March 2011. The conflict has killed more than 220,000 people and wounded at least 1 million, according to the United Nations.
The once-popular resort city is one of the rebels' last strongholds along the border. It was part of a major supply route for weapons sent by Syria to Hezbollah before the outbreak of the Syrian conflict in 2011.
Violence from the four-year civil war has regularly spilled over into Lebanon.
Shells fired by rebels into Damascus struck several neighborhoods, including the central Baghdad Street district. Another shell hit Damascus' famous Dama Rose hotel, previously Le Meridien, near the posh neighborhood of Abu Rummaneh.
The shelling caused damage to the hotel, shattering some of its windows. The Syrian state news agency reported that one person was killed and two others were wounded.
Some material for this report came from AP, AFP and Reuters.