The Latest on developments in the civil war in Syria (all times local):

2:30 p.m.

Syrian activists say that airstrikes outside a school in the northern, rebel-held province of Idlib have killed 17 people, mostly children.

The Idlib News network says the airstrikes hit as the children gathered outside a school complex in the village of Hass, in northern Idlib, on Wednesday.

The group says most of the casualties are children and that there are fears the death toll could rise further as some of the wounded are in critical condition. The Britain-based Syrian Observatory for Human Rights put the death toll at 22, including 14 children. It also says the death toll is likely to rise.

Idlib is the main Syrian opposition stronghold, though radical groups have a large presence there also. It has been regularly hit by Syrian and Russian warplanes as well as the U.S.-led coalition targeting Islamic State militants.

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10:30 a.m.

Turkey's state-run news agency says a helicopter believed to belong to Syrian government forces has dropped barrel bombs in a deadly attack on Turkey-backed opposition forces in the border area.

The Anadolu Agency, quoting military officials, reported on Wednesday that two opposition fighters were killed in the attack in the village of Tall Nayif in northern Syria while five others were wounded. The agency didn't say when the attack happened.

Turkey sent troops and tanks into Syria in August to support Syrian opposition forces efforts to clear the border area of Islamic State fighters.

Ankara is also seeking to contain the U.S.-backed Syrian Kurdish forces fighting IS. Turkey says the Kurdish forces are linked to Turkey's outlawed Kurdish insurgents and the Turkish government considers both to be terrorist groups.