The Udai hospital was damaged during the Jan. 29 airstrikes by government forces on the town of Saraqeb in Syria’s northwestern province of Idlib. (Omar Haj Kadour/AFP/Getty Images)

Pro-government warplanes carried out a torrent of airstrikes Monday against a ­rebel-held province in Syria after the country's opposition refused to attend a Russian-sponsored peace conference.

In the northern town of Saraqeb, in the province of Idlib, residents said bombing raids began in the early morning, first hitting a marketplace, then a hospital treating the casualties and civilian homes.

"I have two children, and every time we hear the planes we hide together in the corner of the house. That's our daily life now," said Muhammad Bakkour, a 23-year-old media worker in Saraqeb. "Every time my children hear the jets, they start to scream. There is nothing we can do to help them."

The White Helmets civil defense group said that at least 15 people had died. An additional 25 were wounded, according to local doctors and activists. Civil defense workers said the raids were carried out by Russian aircraft.

The attacks took place as hundreds of delegates met in the Russian resort town of Sochi for a congress that Moscow has billed as a chance to discuss a political framework for a postwar Syria. Most of the country's political opposition is boycotting that meeting, citing a lack of commitment from the Syrian government to an ongoing United Nations peace process, and only a fraction of the 1,600 invitees were in attendance.

With the U.N. talks achieving little success, the Sochi conference is part of a broader Russian push to consolidate influence in the region and hammer out a road map to end the almost ­seven-year conflict.

With the help of Russia and Iran, the Syrian military has regained much of the territory it lost to opposition groups after a popular uprising in 2011. Monitoring groups say that as many as half a million people have been killed since the conflict began.

Fares Bayoush, a rebel commander who had been invited to Sochi as a delegate, described Monday's violence in Idlib as a message from the Russian and Syrian authorities. "They are saying that if we come to Sochi, there will be no compromises and we must accept the regime. But if we don't, the result will be what we have seen today in Idlib."

For years, Saraqeb's residents had described their town and the surrounding province as a safe haven, the largest enclave remaining under opposition control and a destination for activists, journalists, medics and fighters who felt unable to stay in their home towns as government forces took control. 

According to the United Nations, Idlib is home to more than 2.3 million people, almost half of them displaced from elsewhere in the country.

"We used to welcome in people in here" said Omar al-Saud, a local aid worker. "Now we have no idea where to run."

Hundreds of thousands of civilians are penned into a shrinking swath of territory as government forces advance from the southeast and al-Qaeda militants active in the enclave turn the screws on those who do not submit to their rule. According to the Syrian Network for Human Rights monitoring group, at least 318 civilians have been killed in the violence.

More than 240,000 people have fled fighting since mid-December, the United Nations says. With the Turkish border sealed to the north, the displaced are running out of places to go. 

They are packed into houses and abandoned buildings or sleep in the open air even as rainstorms swirl.

Idlib is one of four rebel-held areas where violence was supposed to have ceased. Under the terms of a deal struck by Russia, Iran and Turkey — three key sponsors of Syria's globalized war — Idlib was designated last year as a de-escalation zone where pro-government troops would end their military campaign, ­except against forces of the ­Islamic State and al-Qaeda-linked groups.

"De-escalation must be viewed as the latest iteration of the government of Syria's long-term strategy of cynical manipulation of cease-fires and of forced submission of geographic areas," said Emma Beals, an independent analyst based in Beirut. "Their strategic aims have not changed, and so it's unlikely that their methods will." 

In interviews, residents of Idlib and surrounding provinces spoke of fear and despair as the catastrophe burgeons.

"People are waiting for their turn to die," Saud said. "We are very tired."

Another man, who spoke on the condition of anonymity out of concerns for the safety of relatives living in government-controlled areas, said he had arrived in Idlib five months ago with his wife and five children. When an airstrike struck their house, the two oldest boys suffocated under the weight of the shattered concrete. Their infant daughter was never found.

"I thought that night would make me crazy. We threw aside so many rocks that our hands were bleeding, but we couldn't find her," he said. 

Save the Children said the recent surge in displaced people is one of the worst of the conflict. Alun Macdonald, a spokesman for the group, said that many had fled so fast that they carried only the possessions they could throw quickly on the back of a truck.

Zakaria reported from Istanbul. Suzan Haidamous in Beirut and Heba Habib in Stockholm contributed to this report.