Russian air strikes have killed at least 10 civilians in Syria's Idlib Province, the opposition's last stronghold, activists say, an allegation quickly rejected by Moscow.

The Syrian Observatory for Human Rights and the Syrian Civil Defense said on January 30 that a hospital and a bakery were struck in the overnight attack in the town of Ariha, amid Syrian government advances on the enclave that had been controlled by rebel forces for nearly eight years.

They said women and children were among those killed and wounded.

Russia's Defense Ministry denied the reports, saying Russian aircraft did not carry out any combat tasks in the area.

Russia-backed Syrian government forces have pressed ahead with its offensive in Idlib in recent weeks.

The U.S. special envoy for Syria, James Jeffrey, said 200 air strikes by Syrian and Russian warplanes had hit the region in the last three days alone.

UN humanitarian chief Mark Lowcock said on January 29 that at least 20,000 people were displaced in the previous two days and 115,000 left their homes in the past week, bringing total of those uprooted by the violence since December to 390,000.

Earlier, President Recep Tayyip Erdogan said Turkey was losing patience with the military assault in Idlib and accuse of Russia of "not honoring" agreements aimed at stemming the violence there.

Turkey and Russia, which support opposing sides in Syria's conflict, have agreed to work toward de-escalating the fighting in Idlib and creating a demilitarized zone.

Based on reporting by AP and AFP