A Syrian military helicopter was shot down by a Turkish jet fighter on Monday after it strayed over the border, both countries said.
Nato-member Turkey's deputy prime minister, Bulent Arinc, said the helicopter flew more than a mile into his country’s airspace and crashed after it was hit by missiles fired by the warplane.
Rami Abdul-Rahman, director of the Syrian Observatory for Human Rights, said rebel fighters captured one of two airmen on board, while the fate of the other was unclear.
Turkish Foreign Minister Ahmet Davutoglu, speaking in Paris after meetings about Syria with his counterparts from other countries, said Monday's encounter should send a message.
“Nobody will dare to violate Turkey's borders in any way again,” he said, according to Turkey’s state run news agency Anatolia. “The necessary measures have been taken.”
Syria accused Prime Minister Tayyip Erdogan’s government of trying to escalate tensions along the border.
“The hasty response from the Turkish side - especially as the aircraft was on its way back and was not charged with any combat missions - is proof of the true intentions of Erdogan's government toward Syria to increase tensions and escalate the situation on the border between the two countries,” Syria's armed forces said in a statement reported by the state news agency SANA.
Meanwile, David Cameron warned that the world may yet feel “shame” at not taking further action in Syria as he launched a bid to ensure a “permanent and fitting” British memorial to the Nazi Holocaust.
The Prime Minister defended his support for military action against Syrian President Bashar Assad's regime in a speech at a dinner to mark the 25th anniversary of the Holocaust Educational Trust.
He told the dinner that one of the main lessons to learn from the Holocaust was “the lesson of not standing by”, adding “with me as Prime Minister, Britain will never stand by”.
“It's an extraordinary human emotion but somehow when genocide is taking place the shame of not acting sometimes doesn't quite register properly until afterwards,” he said.
“When we look back at Srebrenica and Rwanda [genocides], we wonder now why we didn't do more at the time. When something truly terrible happens, it's as if we put up a defence mechanism and try and rationalise why we are powerless to act.
“The same could so easily be said of Syria.”
The White House said on Monday that a United Nations’ report that confirmed the use of chemical weapons in an attack in Syria last month bolstered the U.S. argument that the Syrian government was responsible.
National security adviser Susan Rice said that the technical evidence in the report, including that the sarin nerve agent was high-quality and that a particular rocket was used in the attack, was significant.
The conclusion “reinforces our assessment that these attacks were carried out by the Syrian regime, as only they had the capability to mount an attack in this manner”, she said.