Children among those killed as government forces resume offensive against last rebel-held province in northwest Syria.

At least nine civilians were killed in Syrian government air raids in northwest Idlib province as its forces and their Russian allies continued bombarding the last rebel-held stronghold for a sixth consecutive day.

The attacks on Sunday took place in the towns of Kafr Nabl and Khan Sheikhoun, according to the Syrian Civil Defense, also known as the White Helmets.

Russian warplanes struck a hospital in Idlib province’s rebel-held village of Hass, knocking it out of service, the Britain-based Syrian Observatory for Human Rights war monitor said.

The opposition-run activist collective Baladi News also reported the air strike on the hospital, adding it was not clear if there were casualties.

The Observatory said since the early hours of Sunday, Russian aircraft carried out more than 50 air strikes on Idlib and nearby Hama province.

The latest fighting has killed dozens of people and displaced tens of thousands in Idlib and nearby rebel-held areas, who fled to safer regions further north. It’s the heaviest fighting in months and has raised fears the government may launch a wider offensive to retake the country’s last major rebel stronghold.

Attacks on hospitals and clinics in the past have preceded major government offensives on rebel-held areas, including the 2016 attack on the northern city of Aleppo and last year’s offensive on eastern suburbs of the capital, Damascus.

‘Systematic targeting’

Two people killed in Kafr Nabl were Ahmed al-Rahal, 50, and Hussein al-Deiri, 38, who worked as a medic.

Another seven lost their lives in Khan Sheikhoun, including a woman and two children, Ahmed al-Sheikho, spokesman for the Syrian Civil Defense in Idlib, told Al Jazeera.

Syrian forces with Russian military assistance stepped up an aerial bombardment campaign on April 26.

Since then at least 44 civilians have been killed, according to the group.

In a statement, Syrian Civil Defense warned against what it described as “a real disaster” for civilians, who do not have access to safe areas for shelter.

“There is a systematic targeting of camps to which civilians resort escaping death,” the group said.

‘Terrorist’ positions

Idlib is held by an array of rebel groups, including Hay’et Tahrir al-Sham (HTS), a coalition of fighters including those formerly affiliated with al-Qaeda.

The province is home to about three million people and represents the last big piece of territory held by rebels opposed to Syrian President Bashar al-Assad.

The official SANA news agency said on Sunday that the Syrian army had targeted “terrorist” positions in Idlib and its surrounding areas.

But the UN humanitarian coordinator said schools, health facilities, and residential areas have been hit and government forces are employing the worst barrel bombing in at least the last 15 months.

Last year, the Syrian government, backed in the war by Russia and Iran, was poised to mount a major offensive into parts of the northwest, including Idlib and adjoining parts of Hama and Aleppo provinces, raising concerns of a humanitarian catastrophe.

The attack was postponed after Russia struck a deal with Turkey that included the creation of a “demilitarised zone” in the region.

Russia is the government’s strongest ally and Turkey backs some rebel groups and has troops on the ground in the northwest.

Turkey has been negotiating with Russia to halt the air raids with little success.

State news agency SANA quoted an unnamed Syrian military official as saying insurgents are preparing to launch an offensive on government-held areas, warning such an attack “would mark the beginning of their end”.

“Any action taken by the Syrian Arab Army is legitimate since there has been no commitment to agreements reached,” a Syrian security official was quoted as saying by the government-run Syrian Central Military Media.

Additional reporting by Mohammed Khalaf in Idlib