A Syrian government delegation arrived in Geneva on Friday to join a new round of U.N.-mediated peace talks underway with an umbrella opposition group that seeks to find a resolution to the country's five-year civil war.

The arrival of the Damascus team, led by Syria's U.N. Ambassador Bashar Jaafari, comes amid escalating fighting between government forces and insurgents in northern Aleppo province that has killed 34 fighters on both sides over the past 24 hours.

The Britain-based Syrian Observatory for Human Rights said of those killed, 14 were pro-government fighters and 20 were militants, including members of Syria's Al Qaeda affiliate known as the Nusra Front.

The Al Qaeda branch and its more powerful rival, the Islamic State group, are not part of a cease-fire that went into effect at the end of February. The U.S. and Russia-backed truce has held in most of Syria, except in the north, where it has practically collapsed. The Nusra Front is deeply rooted in the areas in northern Syria controlled by opposition forces, complicating the oversight of the truce.

ISIS militants have clashed with both rival insurgents and pro-government forces in Aleppo, making a wide advance on opposition-held territory along the Turkish border, the Observatory said Thursday.

The New York-based Human Rights Watch said Turkish border guards fired on hundreds of Syrian civilians fleeing the ISIS onslaught on Thursday and heading for a wall at the border. The rights group urged Ankara to allow thousands of Syrians fleeing to cross into Turkey to seek protection.

"As civilians flee ISIS fighters, Turkey is responding with live ammunition instead of compassion," said Gerry Simpson, senior refugee researcher at Human Rights Watch. ISIS is an alternate acronym for the Islamic State group.

"The whole world is talking about fighting ISIS, and yet those most at risk of becoming victims of its horrific abuses are trapped on the wrong side of a concrete wall," he added.

Turkish officials say they were aware of the report but had no immediate response. There was no information whether any of the civilians were hurt in the shooting.

The latest IS advance has displaced 30,000 already-displaced civilians north of Syria's largest city, Aleppo, the provincial capital.

The Syrian opposition High Negotiations Committee, which is negotiating in Geneva, has accused the Syrian government of over 2,000 breaches of the cease-fire in deadly attacks on opposition areas.

U.N. Special Envoy Steffan De Mistura has said he hopes for a substantive round of "proximity talks" on a transitional government to end the war. The two warring Syrian sides do not actually talk to one another in Geneva but the U.N. envoy shuttles between them.

The most obvious public difference between the two sides revolves around the fate of President Bashar Assad. Opposition representatives have insisted that Assad be removed from power as part of any peace deal, while government officials have declared Assad to be a red line.

This round of talks began Wednesday in Geneva but the government said it was delayed because of parliament elections that were held this week in government-controlled areas of Syria. The opposition has dismissed the balloting as a sham and said it could further undermine the peace talks.