Nato is to meet in emergency session after Syria shot down a Turkish plane - an act condemned¹ by Turkey as a "serious threat" to regional peace.

叙利亚击落一架土耳其飞机——土耳其称此举是对地区和平的“严重威胁”。北约因此召开紧急会议。

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Rescue teams from Turkey and Syria are still searching for the wreckage of the plane
In a letter to the UN Security Council, Turkey described the incident as a "hostile act by the Syrian authorities against Turkey's national security".

Turkey's deputy prime minister said it "would not go unpunished", but stressed it was not seeking military action.

Damascus insists the F-4 Phantom³ jet was shot down inside Syrian airspace.

In the letter to the Security Council, Ankara said the shooting down of its F-4 reconnaissance（侦查，勘测） plane was "a serious threat to peace and security in the region".

The BBC's Barbara Plett at the UN says the letter does not ask the council to take any action.

Turkish PM Recep Tayyip Erdogan is expected to outline his next step when he addresses parliament on Tuesday.

Unknown intruder

Turkey, a Nato member, has requested a meeting of the alliance's ambassadors in Brussels after invoking⁴ Article 4 of Nato's founding treaty, which entitles any member state to request consultations⁵（磋商，咨询） if it believes its security is threatened.

This is believed to be only the second time in Nato's history that a member state has invoked⁶ Article 4. In 2003, Turkey asked for Nato assistance to ensure its security in the run-up to the Iraq war.

A Nato official quoted by AP news agency said Turkey's Nato envoy⁷ would inform other ambassadors of the details of the incident at Tuesday's meeting.

The envoys⁸ are then expected to discuss Turkey's concerns but not decide on anything specific, said the official.

The North Atlantic Council - which consists of ambassadors from all 28 Nato countries - works by consensus⁹ and all members must approve any action.