(Updates, recasts)
BRUSSELS, Oct 9 (Reuters) - The head of NATO said on Tuesday that the 28-member military alliance had plans in place to defend Turkey against attack from Syria if necessary, but that he hoped the two countries would find a way to stop tensions escalating.
NATO ambassadors threw their support behind Turkey in an emergency meeting last week after Syrian shells struck a border town in Turkey killing five civilians.
The two neighbours have repeatedly exchanged fire since then, the most serious outbreak of cross-border violence since Syria's revolt against President Bashar al-Assad erupted 18 months ago.
"We have all necessary plans in place to protect and defend Turkey if necessary," Secretary-General Anders Fogh Rasmussen told reporters before a meeting of the alliance's defence ministers in Brussels.
On Monday, Turkish President Abdullah Gul said the "worst-case scenarios" were now playing out in Syria and that Turkey would do everything necessary to protect itself.
Gul said that the violence in Turkey's southern neighbour, where a revolt against Assad has evolved into a civil war that threatens to draw in regional powers, could not go on indefinitely.
U.N. Secretary-General Ban Ki-moon said on Monday the escalation of the conflict along the Turkey-Syria border and the impact of the crisis on Lebanon were "extremely dangerous".
The Turkish army fired back on Monday for a sixth day after a shell from Syria flew over the border and has bolstered its presence along the 900-km (560-mile) frontier in recent days.
Rasmussen commended the Turkish government for its restraint, saying he hoped the parties would avoid an escalation of the crisis.
"Obviously Turkey has a right to defend herself within international law," he said. "I would add to that that obviously Turkey can rely on NATO solidarity."
Turkey joined NATO in 1952.
(Reporting by Adrian Croft; Writing by Sebastian Moffett; Editing by Andrew Osborn)
Keywords: NATO TURKEY/RASMUSSEN