The Observatory said the attacks involved Turkish drones.
Geir Pedersen says the two co-chairs of the constitutional committee from President Bashar Assad's government and the leading opposition have agreed to meet again on November 25, and that delegations would in coming weeks "hopefully come up with a work plan".
Pedersen wrapped up a week of talks with a 45-person drafting committee on Friday hailing a "very good beginning", though he emphasized that the committee "in itself is not a solution to the conflict". They further added that they would continue their cross-border offensive against Kurdish fighters until they leave the region.
There was no immediate comment from the Russian or Turkish military about the incident. The helicopters flew east from the Kuweires air base to Ayn Issa and Raqqa and then back.
He said 13 members of the entourage were now in Turkish detention.
Soylu said the extraditions would start Monday.
Turk authorities had said at the beginning of this week that they will demand a visit to the US on accepting vast genocide of Armenians as mass killing that happened a century ago and on admiring sanctions imposed on Turkey. The Kurdish groups called in Syrian government forces to halt Turkey's advance.
Earlier this week, Soylu said Turkey had almost 1,200 foreign members of Daesh in custody, and had captured 287 during its recent operation in northern Syria. Videos circulating online showed the group trying to mount one of the vehicles and then the men shouting, apparently after the man is run over.
Hungarian Prime Minister Viktor Orban pledged his support for Turkey's plans for a so-called safe zone in northern Syria on Thursday during an official visit from Turkish President Recep Tayyip Erdogan.
Intense clashes broke out Saturday between Syrian government troops and Turkish-led forces in northeast Syria, the country's state media and an opposition war monitor reported.
"The Hungarian government appears to perceive Turkey as an emerging, key geopolitical player, not only in Syria but also in southeastern Europe and the broader Middle East", said Daniel Hegedus, an analyst with the German Marshall Fund of the United States.