Air strikes killed at least 28 civilians Thursday in a camp for the displaced in northern Syria near the Turkish border as a 48-hour ceasefire took hold in Aleppo.

Russian servicemen in sand-colored fatigues sit by phones and computer screens at a base in northwestern Syria, monitoring a ceasefire often on the brink of collapse.

In coordination with a U.S. center in the Jordanian capital, soldiers at Russia's Hmeimim airbase record breaches of the truce -- brokered by Moscow and Washington -- from barracks converted into a makeshift call center.

Prime Minister David Cameron said Wednesday he would let more unaccompanied Syrian children come to Britain after a campaign led by a peer who fled the Nazis in the 1930s.

The U-turn came as the government tries to head off what had been looking like a probable defeat in a parliamentary vote next week on the issue of Syrian minors.

Turkey is ready to send ground troops into Syria if necessary, Prime Minister Ahmet Davutoglu said on Wednesday, after weeks of deadly rocket strikes on a Turkish region from jihadists across the border.

"If it becomes necessary then we will send the ground forces," Davutoglu told Al-Jazeera television in an interview, when asked if Turkey was mulling sending troops to Syria.

France called Monday on the International Syria Support Group to hold urgent ministerial-level talks to restore the country's tattered ceasefire, condemning deadly air strikes by the Damascus regime.

Paris urged the 17-nation ISSG to "restore the ceasefire, reaffirm the need to protect civilian populations... and give a chance to negotiations towards a political settlement," said foreign ministry spokesman Romain Nadal.

The United States Saturday demanded that Syrian President Bashar Assad's forces halt their bombardment of Aleppo and help restore a nationwide ceasefire, with Secretary of State John Kerry due to head to Geneva for talks on the conflict.

Terrified residents fled a new wave of air strikes on rebel-held areas of the divided city as key regime backer Russia rejected calls to rein in its ally.

The United States and Russia have agreed on a "freeze" in fighting along two major fronts in Syria, but not in war-ravaged Aleppo, the Syrian and Russian militaries said Friday.

Fighting in the rebel bastion of Eastern Ghouta, near Damascus, and the province of Latakia is set to halt at midnight on Friday (2100 GMT).

The United Nation's aid chief on Thursday strongly appealed to world powers to revive the ceasefire in Syria and put an end to the "massive human suffering" that has deprived millions of people of food and medicine.

"We must all be ashamed this is happening on our watch," Stephen O'Brien told the Security Council during a meeting on the appalling humanitarian crisis from the five-year war.

A leading pro-government newspaper in Syria said on Thursday that the army is preparing a major offensive to recapture the whole of second city Aleppo and its surrounding province.

The editorial in Al-Watan came as fighting intensifies in and around the divided city despite a February ceasefire brokered by Russia and the United States.

A Syrian opposition group tolerated by President Bashar Assad's regime said Tuesday it had asked the U.N. to merge all opposition factions into one delegation at the next round of peace talks.

The comments came from Syria's former deputy premier Qadri Jamil, who was sacked by Assad in 2013 and now heads the so-called Moscow Group, an opposition faction close to the Kremlin which has met repeatedly with U.N. envoy Staffan de Mistura at negotiations in Geneva.