BEIRUT — Among the streams of refugees seeking safety from the chaos of war-torn Syria, one stood out: A 4-year-old boy, wandering alone in the wilderness.

A United Nations worker on the Jordanian border Sunday tweeted a heartbreaking photo of 4-year-old Marwan, being rescued by aid workers after the boy had become briefly separated from his family.

Andrew Harper, a representative to Jordan for the United Nations High Commissioner for Refugees, tweeted the picture Sunday, one of a string of postings he’s made over the last months documenting what he has called “an endless tide” of refugees fleeing the conflict, toting only what few possessions they can carry.

Here 4 year old Marwan, who was temporarily separated from his family, is assisted by UNHCR staff to cross #Jordan pic.twitter.com/w4s2mrNnMY — Andrew Harper (@And_Harper) February 16, 2014

But this story had as happy an ending as possible for those displaced by the fighting: Harper on Monday tweeted “Marwan was safely reunited w his mother soon after being carried across the #Jordan border.”

It wasn’t initially clear how long the child had been separated from his family. But a Guardian reporter tweeted Monday evening that a UNHCR official on the scene said little Marwan was only about 20 steps behind his family after being becoming lost during the confusion of the crossing.

The three-year-old Syrian conflict has killed more than 130,000 people and is destabilizing the country’s neighbors. The mainly Sunni Muslim rebels have drawn support from radical Sunni groups such as al Qaeda and other foreign militants.

Just to let you know that Marwan was safely reunited w his mother soon after being carried across the #Jordan border pic.twitter.com/h1XskyhWgz — Andrew Harper (@And_Harper) February 17, 2014

Meanwhile, Secretary of State John Kerry on Monday blamed the Assad government for stalling Syrian peace talks and pressed Russia to stop supplying it weapons, telling Moscow it needed to be part of the solution.

International mediator Lakhdar Brahimi said in Geneva on Saturday that the first two rounds of peace talks had not made much progress but that the two sides had agreed on an agenda for a third round at an unspecified date.

“The regime stonewalled. They did nothing except continue to drop barrel bombs on their own people and continue to destroy their own country. And I regret to say they are doing so with increased support from Iran, from Hezbollah and from Russia,” Kerry told reporters in Jakarta on Monday during a trip to Asia and the Middle East.

Using unusually strong language, Kerry said: “Russia needs to be a part of the solution and not be contributing so many more weapons and so much more aid that they are in effect enabling Assad to double-down, which is creating an enormous problem.”

Assad is still trying to win Syria’s civil war militarily rather than find a solution through peace talks, he said.

“It is very clear that Bashar al-Assad is continuing to try to win this (on) the battlefield rather than to (go) to the negotiating table (with) good faith.”

Also Monday, the Western-backed rebel movement the Free Syrian Army announced it was replacing its military chief with an experienced, moderate field commander from the south. The shakeup comes after months of losses to Syrian forces and Islamic extremists.

The opposition reluctantly agreed to participate in two rounds of peace negotiations in Geneva, hoping it would convince the U.S. of the futility of a diplomatic track to end the country’s three-year conflict. By revamping the opposition’s moderate forces, it hopes to encourage its reluctant U.S. and European allies to send them anti-aircraft weapons to challenge Assad’s monopoly on air power.

Brig. Gen. Abdul-Ilah al-Bashir replaces Gen. Salim Idris, a secular-leaning moderate who was criticized by many in the opposition for being ineffective and lost the confidence of the U.S. and its allies, particularly after Islamic extremists seized a weapons depot from moderate rebels. The move was announced Monday in a statement by the FSA’s Supreme Military Council.

Al-Bashir, who previously headed the group’s operations in the southern province of Quneitra on the border with the Israeli-occupied Golan Heights, is considered a moderate Islamist. He hails from the region’s most powerful al-Nuaimi tribe, giving him influence among Syria’s conservative rural areas, where tribal connections are important.

Rebels say he has vast knowledge of the areas south of Damascus where he served as an army commander until defecting to the opposition in 2012. His son Talal, also a rebel, was killed in battle with government forces in Quneitra last year.

In speeches, al-Bashir has said he supports a democratic Syria.

“The value of this man to the rebels is enormous. He was the commander of the Syrian army in the south, which included Daraa province and Golan area. These are the nearest points to Damascus,” said Mustafa Alani, the director of the security department at the Geneva-based Gulf Research Center.

In rebel-held parts of northern Syria where Islamic rebel groups prevail, al-Bashir’s appointment was met with a shrug.

“Most of the factions on the ground are mostly of the Islamic Front who don’t really care that Idris was fired, or that Bashir was appointed,” said Akram al-Halabi, spokesman of the Tawhid Brigades, part of the Islamic Front.

“The people lost hope in the FSA a long time ago,” he said.

With Associated Press and Reuters