UN seeks creation of humanitarian corridors in northwestern Syria, expressing horror at regime offensive there, while Ankara-Moscow talks on Idlib crisis end without a breakthrough.
Syrian regime air strikes have hit hospitals and displaced persons' camps in the northwest Idlib and killed about 300 civilians as regime leader Bashar al Assad's forces press forward with an assault against the last opposition and rebel stronghold, the United Nations said on Tuesday.
The remarks came as talks in Moscow between Turkey and Russia to ease the crisis in the region ended without a breakthrough.
UN officials said relief agencies were overwhelmed by the humanitarian crisis as nearly one million civilians, most of them women and children, had fled towards the Turkish border in bitter winter conditions to escape the onslaught.
"Civilians fleeing the fighting are being squeezed into areas without safe shelter that are shrinking in size by the hour. And still, they are bombed. They simply have nowhere to go," UN human rights chief Michelle Bachelet said in a statement.
The statement said Bachelet was "horrified" by the unfolding humanitarian crisis.
"How can anyone justify carrying out such indiscriminate and inhumane attacks?" Bachelet said.
Bachelet called on all parties to open humanitarian corridors for the safe passage of civilians, many of whom are stranded in opposition-held areas.
"They are now at a higher risk than ever, with little hope or guarantees for a safe and voluntary return to their areas of origin or areas of their choice," she said.
Air strikes and failed talks
The Syrian regime and Russian warplanes meanwhile kept up raids on the town of Darat Izza in Aleppo province on Tuesday, witnesses said, one day after two hospitals there were badly damaged.
At Al Kinana Hospital, blown-out walls and dust-covered medical cables and supplies were strewn about the hospital after two staff were wounded on Monday, witnesses said.
Appearing on national TV on Monday, Assad said the rapid regime military gains presaged the eventual defeat of the nine-year-old insurgency against him although it could still take time.
The offensive has also disrupted fragile cooperation between Ankara and Moscow, who back opposing factions in the war. They began a new round of talks in Moscow on Monday after demands by Ankara that the Syrian regime should back down and a ceasefire be put in place.
The second day of those talks in Moscow ended on Tuesday without a concrete outcome, Turkey's presidential spokesman said.
Ibrahim Kalin said no breakthrough was reached, adding that Turkey rejected proposed documents and maps by Russia.
Kalin said changing the location of Turkey's military observation posts in Idlib is "out of question", adding that Ankara will continue military support and dispatches to safeguard Idlib and the civilians.
He also warned of a resounding response in case of a fresh attack on Turkish soldiers "as we did in the last few weeks."
Ankara's policy in Idlib is based on the 2018 Sochi deal reached with Russia, he said, adding "returning to the Sochi deal is the baseline of Turkey's policy for Idlib."
UN human rights spokesman Rupert Colville, asked if Syria and its ally Russia were deliberately targeting civilians and protected buildings, said, "The sheer quantity of attacks on hospitals, medical facilities, and schools would suggest they cannot all be accidental."
The attacks could constitute war crimes, Colville told a briefing in Geneva.
The UN human rights office said it had recorded 299 civilian deaths since January 1, about 93 percent caused by the Syrian regime and its allies.
The swift advance of regime troops, backed by Russian air strikes, through northwest Syria has also caused the biggest displacement of the war as people flee towards a shrinking pocket near the Turkish frontier where opposition forces hold their last strongholds.
A UN spokesman, David Swanson, said close to 900,000 people have fled conflict zones in Idlib province and western Aleppo since December, more than 80 percent women and children.
Many have been unable to find shelter and are forced to sleep outside in freezing temperatures and burn plastic to stay warm, risking disease and death.
"Only half of all the health facilities in the northwest are still functioning now," Swanson said.
'Scorched earth policy'
Hurras Network, a Save the Children partner in Idlib, said seven children including a seven-month-old baby had died from freezing temperatures and bleak conditions in camps for the displaced.
The Syrian regime said on Monday it had taken full control of dozens of towns in the Aleppo countryside.
The M5 highway linking Damascus to Aleppo, the focus of recent fighting, was reopened to civilian traffic on Tuesday after regime forces recaptured it last week, the Syrian Observatory war monitor reported.
The opposition also said air strikes in southern areas of Idlib province had left dozens of towns and villages in ruins in what it called a "scorched earth policy."
Alarmed by the new refugee crisis on its border, Turkey has sent thousands of troops and hundreds of convoys of military equipment to reinforce its observation posts in Idlib, established under a 2018 de-escalation agreement with Russia.
Trucks carrying aid supplies still cross from Turkey into northern Syria in a UN relief operation, the UN Office for the Coordination of Humanitarian Affairs said on Tuesday.
About 525,000 displaced children are among those trapped, the UN Children's Fund (UNICEF) said.
The Idlib region, including parts of neighbouring Aleppo province, is home to some three million people, half of them already displaced from other parts of the country.
The regime onslaught that began late last year has caused the biggest single displacement of people since the conflict began in 2011.
According to the UN, the war has killed more than 400,000 people since it erupted almost nine years ago, following the brutal repression of popular demonstrations demanding regime change.