Syrian peace talks which fail to address the question of President Bashar Assad's fate are "doomed to failure", a spokesman for the main opposition grouping involved in negotiations said.

Riad Naasan Agha, of the Riyadh-based High Negotiations Committee, said that the talks which are set to resume on April 11 in Geneva must focus on the future of the Syrian leader.

Turkey has detained two shopkeepers accused of savagely beating two teenage Syrian refugees with clubs after spotting them stealing bread in the south of the country, reports said Wednesday.

Security camera footage, which caused outrage on social media, showed two men racing out of their shops in the Hatay region of southern Turkey as the two teens took several loaves of flatbread from a display case.

A Syrian fighter who appeared in a gruesome video cutting out the heart of a regime soldier and eating it has been shot dead by rival rebels, a monitoring group said.

Known by his nom de guerre Abu Sakkar, the rebel reportedly joined the Al-Qaida-affiliated Al-Nusra Front about a year ago, the Syrian Observatory for Human Rights said.

Rebels in Syria are edging closer to the key northern town of Dabiq held by the Islamic State group, pushing the jihadists out of more than a dozen villages, a monitor said Tuesday.

Rebel forces are now within 10 kilometers (six miles) of Dabiq, a town of significant symbolic importance to the jihadists, said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.

Al-Qaida shot down a government warplane over the town of Al-Eis in northern Syria on Tuesday and captured one crew member alive, a rebel source and a monitoring group said.

The rebel source said it was "likely that (Al-Qaida's Syria affiliate) Al-Nusra Front shot down the plane and took the pilot," adding that the plane had been hit by heavy machinegun fire.

Syria peace talks will likely resume in Geneva on April 11, but regime negotiators will only arrive several days later after the completion of parliamentary elections in the country, the U.N. said Tuesday.

United Nations mediator Staffan de Mistura had previously said he wanted to restart the talks on April 9, but noted there was flexibility in the timeline.

Syrian President Bashar Assad has said that he is willing to hold early presidential elections if the Syrian people want them, in remarks released Thursday.

President Bashar Assad said Wednesday that any transitional government in Syria should include both the regime and opposition, as U.N. chief Ban Ki-moon urged greater efforts to tackle the country's refugee crisis.

In an interview published Wednesday, Assad told Russia's RIA Novosti state news agency it would be "logical for there to be independent forces, opposition forces and forces loyal to the government represented" in any transitional body.

France on Tuesday hailed the recapture by Syrian forces of the ancient city of Palmyra as "positive news" but stressed Damascus bore the main blame for the war in Syria.

Syrian regime forces were locked in fierce clashes with Islamic State group jihadists on Tuesday on the outskirts of a key town near the ancient city of Palmyra, a monitor said.

Just two days after seizing Palmyra from IS, pro-government fighters advanced southwest towards the jihadist-held town of Al-Qaryatain.