In addition, a Kurdish-led alliance backed by the US is also confronting government forces in northeastern Syria.

Syrian state news agency SANA said government troops were engaged in fierce battles in Hama province, while Syrian and Russian air forces carried out a series of airstrikes in the northern Hama countryside.

Opposition groups claimed to have captured 14 central villages and towns, including Halfaya, Taybat al-Imam, Maardis and Suran. The UK-based Syrian Observatory for Human Rights also confirmed the information.

After swiftly capturing the city of Aleppo last week, rebel forces led by Hayat Tahrir al-Sham (HTS), along with other militant groups, are advancing south towards the city of Hama, Syria's fourth largest city.

The offensive is one of the biggest since 2020, when fronts in the conflict froze.

UN Secretary-General Antonio Guterres expressed concern over the escalation of violence and called for an immediate halt to fighting. The UN human rights office said a series of attacks had killed many civilians, including women and children, from both HTS and government forces.

Critical infrastructure such as hospitals, schools, food markets and housing for displaced people has been severely damaged. According to the World Health Organization (WHO), the health system in Aleppo is under extreme strain, with thousands of injuries reported in the past few days.

Between November 27 and December 2, 81 civilians were killed in Idlib, including 34 children and 12 women. The number of injured people reached 304, including 120 children and 78 women, according to the Syrian Civil Defense.

The number of functioning hospitals in Aleppo has fallen from 42 to fewer than eight, with minimal operational capacity, the WHO said.

In northeastern Syria, the Syrian Democratic Forces (SDF), a US-backed, Kurdish-led alliance, clashed with government troops near villages on the eastern bank of the Euphrates River, near the provincial capital Deir Az Zor.

The UN says escalating violence has forced 50,000 people to flee their homes in recent days, worsening the humanitarian situation in Syria.

The civil war that has raged since 2011 has entered a new, tense phase, with the largest fighting in years. This escalation has not only affected thousands of civilians but also left Syria in a state of unrest.

Cao Phong (according to AP, Al Jazeera)