BEIRUT (AP) -- Airstrikes believed to have been carried out by Russian warplanes killed at least 18 civilians and wounded dozens more on Sunday in a northern Syrian town held by insurgents, Syrian opposition media reported.
The Britain-based Syrian Observatory for Human Rights said the airstrikes struck the town of Ariha, killing at least 18 people, including four children, and wounding dozens more. The Local Coordination Committees, an activist collective, said the airstrikes struck a busy market, inflicting heavy casualties.
The Observatory, which relies on a network of activists inside Syria, said the airstrike destroyed three buildings in the center of Ariha.
Ariha Today, a Facebook page that covers events in the town, said the airstrikes were carried out by Russian warplanes, killing 40 people and wounding more than 70. Conflicting tolls are common in the chaotic aftermath of violent incidents in Syria.
If Russian warplanes carried out Sunday's strikes it would be one of the deadliest incidents since Moscow began launching airstrikes in Syria two months ago. Opposition activists say more than 400 civilians have been killed by Russian strikes since the air campaign began on Sept. 30.
An amateur video posted online showed several men being treated on the floor of what appeared to be a clinic. Blood stains could be seen on the floor's white tiles. On the street outside, four men could be seen lying near the building, with several young men weeping over them.
Shortly afterward, an ambulance arrived and a wounded man in a wheelchair was carried into the clinic.
The video appeared genuine and corresponded to other AP reporting of the event.
The Observatory reported several other strikes in the northwestern province of Idlib believed to have been carried out by Russian warplanes on Sunday. It said that an office of the Turkistan Islamic Party, a group that consists mainly of fighters from Asian states, was hit in the town of Jisr al-Shughour and that planes struck a relief office for the ultraconservative Ahrar al-Sham group in the town of Saraqib.
The LCC reported airstrikes on a hospital in Idlib, the provincial capital, and other targets in Saraqib.
Russia says its airstrikes are aimed at the Islamic State group and other "terrorists," but Western officials and Syrian rebels say most of the strikes have focused on central and northern Syria, where IS does not have a strong presence.
In the capital Damascus, state media quoted President Bashar Assad as saying that he is determined to continue fighting "terrorism in all its forms" because Syria and its allies are "confident that eliminating terrorists is the main step in bringing about stability to the region and the entire world."
The Syrian state news agency SANA said Assad made his comments during a meeting on Sunday with Ali Akbar Velayati, a top adviser to Iran's supreme leader Ayatollah Ali Khamenei, who arrived in Damascus earlier in the day. Iran has been one of Assad's strongest supporters over the past years.
Syria's conflict has killed more than 250,000 people and wounded more than a million since the start of an uprising against President Bashar Assad in 2011.