Turkey ordered a Syria-bound Armenian plane to land and searched its cargo, airport officials said, in the second such action in a month to prevent the use of Turkish airspace to supply the Syrian military.

The cargo aircraft was searched in the eastern Turkish city of Erzurum in a previously agreed step, as in mid-October when another Armenian plane was allowed to continue its journey after confirmation it was carrying humanitarian aid as stated.

Officials at Erzurum airport said Turkey had allowed the plane to leave after a search of around four hours and that none of the Air Armenia plane's cargo had been seized.

Turkey has become increasingly assertive in challenging Syrian President Bashar al-Assad amid growing tensions along the border.

It banned Syrian aircraft from its airspace in October after saying it had found Russian munitions believed to be destined for Syria's armed forces on board a Syrian plane. (Reuters)