Turkey boosts presence on Syria border The Syrian passenger plane forced to land by Turkey on Tuesday on suspicion of carrying Russian weapons for the Syrian regime Turkey has increased its military presence along its 900km border with Syria, scrambling jets and dispatching scores of tanks in the continuing face-off between Ankara and Damascus. Two fighter aircraft flew along a stretch of the border after a Syrian helicopter bombed the nearby Syrian village of Azmarin, while Turkish media reported that up to 250 tanks were in the border area. The show of force came after days of mounting confrontation between Syria and Turkey, which has also seen Ankara clash with Moscow. On Wednesday Turkish jets forced down a Syrian Airlines flight from Moscow to Damascus, which Recep Tayyip Erdogan, Turkey's prime minister, later claimed was carrying military equipment. That incident followed almost a week in which shells from Syria landed on the Turkish side of the border, with Ankara returning fire. "The Turkish government wants to show domestic public opinion that it can deliver a tough response to the Syrian military," said Nihat Ali Ozcan, a retired Turkish major now at Turkey's Economic Policy Resarch Foundation. It also wants to increase psychological pressure on the Syrian regime so that it does not approach the border. Mr Erdogan set out new rules of engagement in June under which Turkey would retaliate against any Syrian forces approaching the border that were perceived to be a threat - a doctrine some analysts have interpreted as warning Syria to desist from airstrikes within 10km or so of the fronter. But since then Ankara's anger has grown during the continued assault by the regime of President Bashar al-Assad on rebel-held positions close to the border - and tensions reached a new high after a Syrian shell killed five Turkish citizens in a border town this month. Some Turkish officials now suspect that subsequent Syrian shell-strikes on Turkey have been a deliberate attempt to draw Ankara into Syria's increasingly brutal civil war. Turkish officials are also painfully aware that while their own army's show of force on the border is intended to deter Damascus from any such provocations, having large numbers of armed units in such proximity may increase the risk of escalation. Turkey's frustration with Damascus's military activity in the border region has boiled over even as tensions have risen with Russia, one of Mr Assad's most important allies. On Friday Moscow demanded more details about the equipment impounded from the Syrian Airlines flight. Sergei Lavrov, Russian foreign minister, said the plane was carrying a "absolutely legal" cargo of electronic equipment for radar stations. He described the equipment as "dual use" but "not prohibited by international conventions." However, Turkey argues that by shipping defence equipment on a passenger aircraft, the Syrian Airlines flight violated international aviation rules. In addition, while there is no United Nations embargo on supplying defence equipment to Damascus - largely because of a Russian veto - Turkey has said for the past year that it prohibits any such shipments through its territory or airspace. Mr Lavrov added: "No weapons were on that plane and none could have been.. we have absolutely no secrets." A report from Kommersant, the respected Russian daily, suggested that the cargo on board had not been arms but air defence components. The Moscow newspaper said the aircraft contained 12 crates of components to be used in Syria's radar systems, with proper documentation, making the cargo legal according to Russian legislation. Turkish media reports have said the seized equipment included missile parts and military communications equipment, while Mr Erdogan accused an unnamed Russian agency of sending the cargo to the Syrian ministry of defence. Russian diplomats and officials from Rosoboronexport, Russia's state-owned arms exporter, continued to express scepticism that weapons had actually been inside the commercial Syrian Airlines flight, which was forced to make an emergency landing in Ankara early on Thursday morning. Rosoboronexport and Amaz Antei, the state anti-aircraft weapons manufacturer, both denied to the FT that they had any cargo on the flight, including defence components.