Russia has denied Turkish accusations that a Syria-bound passenger plane was transporting weapons. The plane took off from Moscow before being forced to land in Ankara.

Turkish jet fighters intercepted the Syrian passenger airplane on Wednesday night after receiving reports that it was carrying “illegal cargo," according to Turkey's foreign minister, Ahmet Davutoglu, Reuters reported.

"We are determined to control weapons transfers to a regime that carries out such brutal massacres against civilians. It is unacceptable that such a transfer is made using our airspace," Davutoglu told  Zaman  Daily, but he stopped short of outright declaring that the plane was carrying arms, saying merely that the cargo was "banned from transport."

But later, Prime Minister Recep Tayyip Erdogan charged that the plane was carrying war material, The New York Times reported.

“From Russia, an institution equivalent to our Machinery and Chemical Industry [Ministry] has sent military tools, equipment and ammunition to the Syrian Defense Ministry,” he told the semiofficial Anatolian News Agency. “Upon the intelligence received, research there was conducted and it was unfortunately seen that there was such equipment inside.”

Erdogan also said an upcoming visit to Turkey by Russian President Vladimir Putin had been postponed. He said the postponement had no connection with the forced grounding of the plane.

The plane was traveling from Moscow to Syria over Turkish airspace when reports surfaced that it was carrying military equipment and "non-civilian cargo."

The aircraft was escorted to Esenboga airport for security checks, and some hours later was allowed to continue on its journey.

“I think that tension will now develop in the relationship between Russia and Turkey,” a Russian Foreign Ministry official said, according to the New York Times.

“Neither weapons nor any systems or assembly parts for military equipment were or could have been on board the passenger plane," an unidentified source at one of Russia's state arms exporting agencies told Interfax.

However, unconfirmed reports in Turkish media said the confiscated cargo included boxes of military communication equipment, with Turkey’s NTV saying missile parts were also on board the plane.

The tough new stance on Syria by the Turkish authorities follows a mortar attack that killed five Turkish nationals, including three children, in a town on the Turkish/Syrian border last week.

Syria has accused Turkey of "hostile and reprehensible behavior," the Syrian foreign minister told the AFP, and that the plane's grounding was "another sign of the hostile policies of the Erdogan government, which harbors [rebels] and bombs Syrian territory."

"The plane was not carrying any illegal material," Ghaida Abdulatif, head of Syrian Arab Airlines, told reporters in Damascus, the Hürriyet Daily reported. "When the plane was inspected it was clear that there were ... civilian packages with electrical equipment which are allowed to be transported and had been officially registered."

The plane was carrying 37 people, mostly elderly, women and children, Syrian officials claimed. Hürriyet Daily reported that several of the passengers were threatened, beaten up, and forced to sign fake documents saying the plane made an emergency landing.

Davutoglu told Zaman that the passengers were treated "hospitably" and given meals while the plane's cargo was inspected.

The latest incident adds to the worsening relationship between Ankara and Damascus, with both sides already on a heightened state of military alert.