In Damascus, Syrian Foreign Ministry spokesman Jihad Makdessi rejected the Turkish accusations as "absolutely untrue," saying the plane was not carrying ammunition or any illegal cargo. Turkey's decision to force the plane to land amounted to piracy, said Transportation Minister Mohammad Ibrahim Said.
The general manager of the Syrian Civil Aviation Agency also blasted Turkey's forced landing of the plane, calling it "contrary to regulations and aviation norms."
The plane's pilots were not asked to land but were surprised by the Turkish F-16 fighter jets that intercepted the flight, the official, Ghaidaa Abdul-Latif, told reporters in Damascus.
A Syrian Air engineer who was aboard, Haithan Kasser, said armed Turkish officials entered the plane and handcuffed the crew before inspecting packages that he said contained electrical equipment.
The Moscow airport that cleared the Syrian plane for takeoff denied it carried any forbidden cargo.
"No objects whose transportation would have been forbidden under aviation regulations were on board," said Vnukovo Airport spokeswoman Yelena Krylova, ITAR-Tass reported. She said all documentation was in order, though she would not say who sent the cargo.
Meanwhile, family and supporters of two journalists believed to be detained in Syria appealed in Istanbul for their release. Arzu Kadoumi said her husband Bashar Fahmi, a reporter for Al-Hurra network, and his Turkish cameraman, Cuneyt Unal, had been missing for 53 days.
Inside Syria, battles continued in the southern Idlib province that abuts the Turkish border as rebels sought to consolidate control of a strategic town on the country's main north-south highway. Rebels said they captured Maaret al-Numan on Wednesday.
The Britain-based Syrian Observatory for Human Rights said clashes continued Thursday after rebels attacked a military convoy and nearby army checkpoints. The fighting killed more than a dozen people, the Observatory said.
The Observatory also said eight people were killed and another eight wounded when unknown gunmen fired on their bus near the coastal city of Tartous. Syria's state news agency SANA said the men were Syrian workers returning from Lebanon.
In the southern province of Daraa, gunmen shot dead the brother of a member of Syria's parliament while raiding his home, the Observatory and SANA said. The parliament member, Khalid al-Abboud, regularly defends the Syrian regime on TV.
The Observatory said gunmen also killed the son of another legislator, Mohammed Kheir al-Mashi, at his home in Idlib province.
The activist claims could not be independently verified because of restrictions on reporting in Syria.
Meanwhile, state-run Syrian TV reported an explosion in the capital Thursday night near the Ministry of Education and the Military Court. A Syrian official said the blast wounded two people.
Jordans reported from Istanbul. Associated Press reporters Matthew Lee in Washington, Albert Aji in Damascus, and Nataliya Vasilyeva and Max Seddon in Moscow contributed to this report.