UN investigators have accused the US-led international coalition of Russia, the Syrian regime and Kurdish militias of abuses that could amount to war crimes, coinciding with Russian and Syrian shelling in Idlib countryside for the first time since the regime declared a recent ceasefire.

According to a report of the United Nations Commission of Inquiry on Syria that the international coalition led by the United States carried out air strikes in Syria, which caused heavy casualties among civilians, and may amount to war crimes.

The report, which was based on about 300 interviews, satellite images, video and image analyzes since the beginning of this year, said the planes of the Syrian regime and its ally Russia are also waging a bloody campaign apparently targeting medical facilities, schools, markets and farms, which could also amount to To war crimes.

Investigators added that the UN special envoy to Syria gives high priority to the issue of missing persons, detainees and abductees in Syria.

Hani Megally, a member of the International Independent Investigation Commission, said there was international judicial progress outside Syria, adding that arrest warrants had already been issued against security leaders in Syria.

"In this report, we cover war crimes by all parties, and on several occasions we have shown what the SDF and the international coalition have done that we have found war crimes can amount to war crimes."

Meanwhile, Al Jazeera correspondent said that Wednesday witnessed the first escalation since the ceasefire declared by the regime and Russia in Idlib at the end of last month.

The reporter also confirmed the death of one person and wounding others in artillery and rocket shelling by regime forces south of Idlib.