Iraqi pilots who have joined ISIS in Syria are training members of the group to fly in three captured fighter jets, Reuters reported a group monitoring the war as saying on Friday, citing witnesses, Al Arabiya reported.
The group has been flying the planes over a captured Syrian military airport in the northern Aleppo province, said Rami Abdulrahman, who runs the Britain-based Syrian Observatory for Human Rights.
"They have trainers, Iraqi officers who were pilots before for (former Iraqi president) Saddam Hussein," he said. "People saw the flights, they went up many times from the airport."
Meanwhile, U.N. Syria envoy Staffan de Mistura will visit Russia next week, the Moscow-based U.N. information center said on Friday.
Russia, which has stood by Syrian President Bashar al-Assad during the three-year-old conflict, has objected to a U.S.-backed bombing campaign against Islamic State targets in Iraq and Syria, saying they should have been agreed with Assad.
De Mistura is expected to meet Foreign Minister Sergei Lavrov on Oct. 21, RIA news agency quoted Deputy Foreign Minister Gennady Gatilov as saying.