BEIRUT (AP) — The Latest on Syria developments (all times local):

4:30 p.m.

A Syrian war monitor says twin suicide attacks on the offices of a powerful ultraconservative insurgent group in rebel-controlled Idlib province has killed at least 14, raising the death toll from five.

It was not clear who was behind the Sunday attack. Earlier, the Britain-based Syrian Observatory for Human Rights said at least five Ahrar al-Sham members were killed in the village of Tal Touqan. The Observatory said it was a twin suicide attack that targeted the ultraconservative group.

Opposition-operated Baladi News Network quoted a witness as saying at least 15 people were killed in the attack that targeted a group meeting, saying the attackers reached the area on a rigged motorcycle.

Northern Idlib is an opposition stronghold, but an al-Qaida-linked group has the most sway there and it is at odds with Ahrar al-Sham, the powerful ultraconservative group targeted in the attack.

The Observatory and Baladi said a local Ahrar al-Sham leader was among those killed.

3:15 p.m.

Syria opposition activists say a suicide attack in rebel-controlled Idlib province killed at least five members of a powerful ultraconservative insurgent group.

It was not clear who was behind the Sunday attack. Northern Idlib is an opposition stronghold, but an al-Qaida-linked group has the most sway there and it is at odds with Ahrar al-Sham, the powerful ultraconservative group targeted in the attack.

Britain-based Syrian Observatory for Human Rights said at least five Ahrar al-Sham members were killed in the village of Tal Touqan and expected the death toll to rise. A leading member was killed in the attack, according to the Observatory.

Other opposition media platforms, such as Baladi News Network, quoted a witness who said at least 15 were killed in the attack that targeted a group meeting.