No immediate information on casualties from the strike on Rahma hospital in Tal Mannas.
Air strikes hit a hospital in a rebel-held village in northwestern Syria, knocking it out of service early on Wednesday, opposition activists said as regime forces pressed their offensive on the last major opposition stronghold in the war-torn country.
There was no immediate report on casualties from the air strike on Rahma hospital in Tal Mannas, said the Britain-based Syrian Observatory for Human Rights and the Thiqa news agency, an activist collective.
The Observatory said the hospital was struck four times but that it had been evacuated hours earlier.
Earlier this month, UN Secretary-General Antonio Guterres authorised an investigation into attacks on health facilities and schools in the opposition-held enclave, following a petition from Security Council members.
Wednesday's air strike was one of several to hit Idlib province, home to some three million people and the area where regime forces have been on the offensive for months.
The violence came a day after the al Qaeda-linked Hayat Tahrir al Sham militant group pulled out of Khan Shaykhun, as regime forces advanced in the area slowly, clearing land mines and explosives.
Syrian regime forces have been on the offensive in Idlib and northern parts of Hama province since April 30, forcing nearly half a million people to flee to safer areas further north. The fighting also killed more than 2,000 people, including hundreds of civilians.
On Wednesday, the regime forces captured the Teraei Hill, east of the town of Khan Shaykhun.
Syrian regime forces are trying to capture more ground to meet troops marching from the west in order to lay siege on rebel-held towns and villages in the central province of Hama, according to the Observatory.
Activists also reported fighting in the rebel-held areas in the Jabal al Akrad region in the coastal province of Latakia.
The Syrian Response Coordination Group, a relief group active in northwestern Syria, reported that nearly 200,000 people have fled the violence over the past 10 days.