WASHINGTON - Fierce clashes continued Sunday between Syrian government forces and rebel fighters in the northwestern province of Idlib, despite a cease-fire brokered last week by Russia and Turkey.

The recent surge in violence began after Syrian and Russian warplanes resumed their airstrike campaign in Idlib, the Syrian Observatory for Human Rights reported.

The war monitoring group said severe clashes took place Sunday in the southeastern part of Idlib, where rebel fighters and jihadist factions have been trying to regain control of several towns and villages recently recaptured by Syrian government forces and their allies.

Local news reports said at least 28 Syrian government troops and 19 rebel fighters, including 15 jihadists, were killed in Sunday's clashes.

Idlib, the last main rebel stronghold in Syria, is home to nearly 3 million people. The Syrian province is largely controlled by the Islamist militant group Hayat Tahrir al-Sham (HTS), a former al-Qaida affiliate in Syria.

Failed truce

On Jan. 12, Turkey announced a new cease-fire in Idlib after an agreement with Russia. Ankara and Moscow support opposing sides of the Syrian conflict.

Turkish Foreign Ministry said in a statement that Turkey and Russia had agreed on a cease-fire and a halt of ground and air operations in the so-called de-escalation zone in Idlib.

The de-escalation zone was announced in September 2018, after Moscow and Ankara reached an agreement that postponed a planned Syrian government offensive on Idlib and other areas near the Turkish border.

As part of that agreement, Turkey was required to remove all extremist groups from the province, some of which are tied to the al-Qaida terrorist group. But Turkey allegedly has failed to implement its part of the deal.

In April 2019, the Syrian military and its allied militias launched a major offensive to recapture Idlib from rebel forces.

The U.N. says that since then it has documented more than 1,500 civilian deaths, nearly half of them are women and children. Local rights groups, however, say the death toll is much higher.

Jihadi coalition

HTS and several other jihadist groups have joined forces in a coalition to battle Syrian government troops, HTS said in a statement released Friday.

Rami Abdulrahman, director of the Syrian Observatory, says the jihadi coalition in Idlib aims to make a last stand against the Syrian government troops and their Russian allies.

"This alliance will continue and will not end anytime soon now that Turkey has told them to confront the regime forces," Abdulrahman told VOA.

In an interview with CNN Turk Thursday, Turkish Foreign Minister Mevlut Cavusoglu said that Syrian "opposition must protect itself from [Syrian] regime attacks," adding that there have been violations of the Idlib cease-fire that Turkey and Russia agreed on.

In addition to HTS, the so-called coalition includes the Turkish-backed National Liberation Front and several al-Qaida-linked groups such as Ansar al-Tawhid.

"Despite their ideological differences, these groups have always maintained a level of cooperation throughout Syria's war," said Sadradeen Kinno, a Syrian researcher who closely follows Islamic militancy in the war-torn country."

"This time around, however, their alliance is more important than ever before because the ongoing battle in Idlib is a matter of life and death for all these extremist and jihadist groups," he told VOA.

Displaced people

According to the U.N, about 350,000 civilians, mostly women and children, have fled the Russian-backed Syrian military offensive that began in Idlib in early December.

Amina Ose, a senior official at the Kurdish-led administration in northeast Syria, said at least 300 families from Idlib have sought shelter in areas under the control of U.S.-backed Syrian Democratic Forces (SDF).

"We are building a camp near the town of Manbij to host these families. We expect to receive more displaced people from Idlib as the fighting intensifies there," she told VOA.

Other displaced people reportedly have fled to safer areas under rebel control along the Syria-Turkey border.

US Stance

U.S. officials have repeatedly called on the Syrian government and its Russian and Iranian allies to stop their attacks against civilians in Idlib.

"Russia, Syria and Iran are killing, or on their way to killing, thousands of innocent civilians in Idlib Province...," President Donald Trump said in tweet last month.

The United States, which has led a coalition to combat the Islamic State (IS) terror group in eastern Syria, does not have any military presence in northwestern Syria, including Idlib, but U.S. forces have occasionally carried out airstrikes targeting al-Qaida and other militant leaders in Idlib.

In October 2019, the U.S. conducted an operation in Idlib that killed IS leader Abu Bakr al-Baghdadi, who had been hiding in the northwestern Syrian province since March of the same year after the military defeat of his group in eastern Syria.