Turkey seized "objectionable cargo" aboard the Syrian passenger plane which it intercepted en route from Moscow to Damascus on Wednesday, Turkish Foreign Minister Ahmet Davutoglu said, according to an AFP report.
"There is illegal cargo on the plane that should have been reported" in line with civil aviation regulations, Davutoglu was quoted as saying by the Anatolia news agency.
"There are elements on board that can be considered objectionable," he added, without elaborating.
The confiscated cargo might be missile parts, NTV news channel reported.
The plane, carrying 35 passengers on board, would be allowed to leave soon, Davutoglu said.
Meanwhile, Al Arabiya reported, Turkish authorities declared the Syrian airspace to be unsafe and were stopping Turkish aircraft from flying over the civil-war torn country.
TRT television said that a Turkish plane that had already taken off for Saudi Arabia made a detour and landed at a Turkish airport.
The incident occurred in the wake of a week of tension between Turkey and Syria, which began last Wednesday when a Syrian mortar landed in Turkish territory, killing five civilians in Akcakale.
The United Nations Security Council later condemned Syria over the mortar attack on Turkey.