A 45-year-old Syrian man with a Swedish residency permit has been arrested for alleged war crimes in northern Syria, officials said Tuesday.

Haisam Omar Sakhanh, was arrested on Friday and remanded in custody in Orebro, some 200 kilometers (125 miles) west of Stockholm.

Russian media on Tuesday hailed as a political victory President Vladimir Putin's surprise decision to start withdrawing armed forces from Syria as U.N.-backed peace talks resumed in Geneva.

"Russia is setting an example of a peaceful approach to settling conflict," the pro-Kremlin Izvestia daily said on its front page.

Since a ceasefire came into force in Syria, the army and its Russian ally have refocused their air power on targeting jihadist factions, a monitoring group said Monday.

The truce began on February 27 and does not cover the fight against jihadist groups like Islamic State and the Al-Qaida-affiliated Al-Nusra Front.

Russia called Monday for all opposition factions to be represented at the Syrian peace talks in Geneva aimed at ending the country's five-year conflict.

Foreign Minister Sergei Lavrov also hinted that an agreement could be reached to coordinate air strikes between the Russian air force and the US-led coalition to retake key rebel towns.

Agreeing on political transition in Syria is the "mother of all issues," the U.N. envoy for the war-ravaged country said Monday, as a new round of peace talks was set to begin.

Speaking to reporters in Geneva, Staffan de Mistura stressed the importance of getting the talks quickly focused on "the real issues," adding: "What is the real issue? The mother of all issues (is) political transition."

Talks to end Syria's civil war opened in Geneva on Monday, but hopes for a breakthrough remained remote with the sides locked in a bitter dispute over the future of President Bashar Assad.

The U.N.-hosted negotiations, which began a day before the fifth anniversary of the outbreak of the conflict, are the latest effort to end violence that has killed more than 270,000 people and displaced millions.

Top Islamic State group commander Omar al-Shishani has been "clinically dead" for several days after a U.S. air strike in northern Syria, a monitoring group said Sunday. 

French Foreign Minister Jean-Marc Ayrault hit out Sunday at comments by his Syrian counterpart that removing President Bashar Assad would cross a "red line" in the negotiations, describing them as a "provocation" and a "bad sign" for the attempts to find peace.

Muallem said in Damascus Saturday: "We will not talk with anyone who wants to discuss the presidency... Bashar Assad is a red line."

Syria's warring sides prepared Sunday for a new round of peace talks after locking horns over the fate of President Bashar Assad, with the regime insisting his ouster was a "red line" while the opposition vowed to see him go -- dead or alive.

The UN-brokered indirect negotiations are due to begin in Geneva on Monday, the latest international push to find a solution to Syria's five-year civil war, which has killed more than 270,000 people and forced millions from their homes.

Syria's warring sides clashed over the fate of President Bashar Assad on Saturday, with the government vowing his ouster remains a "red line" for looming peace talks while the opposition vowed to see him go -- dead or alive.

The UN-brokered, indirect negotiations due to begin in Geneva on Monday are the latest international push to find a solution to Syria's five-year civil war, which has killed more than 270,000 people.