* Denounces request for Patriot interceptors on border
* Turkey blames Syria's disregard for "any rules of war"
* Rebels make advances but still unable to seize cities
* Assad appears on state TV, looks well
BEIRUT, Nov 23 (Reuters) - Syria on Friday condemned Turkey's request for NATO to deploy Patriot defence missiles near their common border, calling it "provocative", after a spate of clashes there that has raised fear of the Syrian civil war embroiling the wider region.
The 20-month-old uprising against Syrian President Bashar al-Assad has turned increasingly bloody and heavy fighting has often erupted right along Syria's northern border with Turkey. Ankara has repeatedly scrambled fighter jets and responded in kind to stray shells and mortars flying into its territory.
In the first Syrian response to Ankara's request earlier this week, a ministry source told Syrian state television that Damascus would hold Turkey's prime minister responsible for increasing tensions along the frontier.
Turkey's missile request may have riled Damascus and its allies - notably Russia and Iran - because it could be seen as a first step toward implementing a no-fly zone.
Syrian rebels have been requesting a no-fly zone to help them hold territory against a government with overwhelming firepower from the air, but most foreign governments are loath to impose one for fear of getting sucked into the conflict.
The Patriot system is designed to intercept aircraft or missiles. Turkey asked for it after weeks of talks with its NATO allies about how to shore up its 900-km (560 mile) border, where it fears security may crumble as the Syrian army fights harder to contain the rebels - who have enjoyed sanctuary in Turkey.
"Syria stresses its condemnation of the Turkish government's latest provocative step," the ministry source told Syria TV.
The source said that Syria would respect Turkish sovereignty but also said that it "holds (Tayyip) Erdogan responsible for the militarisation of the situation on the Syrian-Turkish border and increased tensions".
NATO chief Anders Fogh Rasmussen said on Thursday that the possible deployment of Patriot missiles was "purely defensive" and would "serve as a deterrent to possible enemies even thinking of attacks".
The U.S.-led Western alliance has had some talks on the Turkish request but no decision is expected before next week.
TURKEY REJECTS SYRIAN CRITICISM
Asked about Syria's remarks, Turkish Foreign Minister Ahmet Davutoglu said Damascus was at fault for heightened tensions by having attacked its own people with tanks and warplanes "without any regard for any rules of war".
"There exists such a situation now right next to Turkey, that (Turkey) has to take its own measures...aimed at defence.
"If this measure is not needed then it will not be used, but if there is any kind of risk to Turkey's security, all kinds of steps will be taken, both within Turkey's national capacity and within the framework of Turkey's membership of NATO. Nobody should have a need to question this," Davutoglu added.
Russia, Syria's main arms supplier, opposes the deployment of surface-to-air missiles. It is not a NATO member and cannot block alliance decisions, but planned talks with NATO about a move it says "would not foster stability in the region".
Analyst Michael Stephens of the RUSI think-tank in Doha said Turkey's request was a symbolic gesture, noting that Patriots could do little to stop incoming mortar fire.
"It could be a first step to a no-fly zone, but what does that take? NATO would need a mandate, which means a United Nations Security Council resolution, and Russia will obviously say no to that," he said.
DEATH TOLL RISES ABOVE 40,000
Western states, keen to avoid another costly Middle East conflict and wary of backing rebels who include Islamist militants, have stayed on the sidelines, although France and Britain formally recognised a newly formed opposition coalition as the sole representative of the Syrians this month.
With no credible peace mediation on the horizon, the number of dead is rising rapidly by the day. The Syrian Observatory for Human Rights said more than 40,000 had died and the actual number may well be higher because both sides appeared to be under-reporting their casualties.
Rebels appear to have been advancing in recent weeks, seizing several military bases in the eastern oil-producing province of Deir al-Zor, Aleppo in the north and even around the capital Damascus.
Their tactics have improved as they focus on controlling roads and sealing off military bases.
Recent rebel gains in Deir al-Zor, including the Mayadeen artillery base on Thursday, have meant notable amounts of arms and a wider swathe of territory passing into insurgent hands.
REBELS STILL LACK FIREPOWER
But rebels still lack advanced heavy weaponry they need to oust Assad's well-armed troops ensconced in the main cities, and remain vulnerable to increasingly frequent air strikes.
Many surface-to-air missiles seized in recent rebel raids seem to be missing some of the equipment needed to fire them, arms experts say. This means the rebels probably have the means only to fire a few anti-aircraft missiles at a time.
"The rebels have made big advances in the countryside and even into the main (Deir al-Zor) city, but they cannot take it," Stephens said. "This is another brick the rebels have taken down, but it is not critical for toppling the regime."
Deir al-Zor province abuts the long Iraqi border but controlling it may not offer the same advantages seen by rebels near the northern border with Turkey, where the fighters can go in and out easily.
Iraqis are slipping in to fight on both sides, reflecting the sectarian faultlines increasingly defining Syria's conflict.
Iraq's majority Shi'ite Muslims largely support Assad, whose Alawite minority, derived from Shi'ite Islam, has dominated the country for 42 years. Sunni Muslims in Iraq generally support the revolt, which is spearheaded by Syria's Sunni majority.
Assad met in Damascus on Friday with Iranian parliament speaker Ali Larijani and said he was pursuing national dialogue even as his forces were "fighting terrorism", which he said threatens to erode Syria's security and regional stability.
The embattled Syrian president looked well in video footage of him with Larijani released by state television.
In Beirut later, Larijani told a press conference that Iran supported democratic change in Syria but not intervention.
"Others want to impose democracy in Syria through the force of weapons and this will only lead to destruction," he said.