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ISTANBUL, Feb 11 (Reuters) - The Turkish lira weakened some 0.6% against the dollar on Tuesday as investors grew increasingly concerned about an escalation of violence between Syrian government forces and Turkish forces in northwest Syria.
Five Turkish soldiers were killed in shelling by Russia-backed Syrian forces on Monday, marking the second deadly attack on Turkish forces in Syria's Idlib province within a week.
The lira weakened as far as 6.04250 against the dollar from a close of 6.0075 on Monday. Its volatility has spiked since a late Friday selloff.
Concerns over Turkey's increased military involvement in Syria have been growing, said Jason Tuvey, senior emerging markets economist at Capital Economics.
"The latest developments certainly raised concern that tensions will continue to flare up," he said, adding that government efforts to artificially prop up the lira would "ultimately... prove futile."
Turkish state banks have sold tens of billions of dollars over the last year to stabilize the lira, which lost 36% of its value in two years following a currency crisis in 2018.
"Given (Turkey's) low foreign exchange reserves, the country's large external debt, it just cannot be sustained for very long at all," Tuvey said.
The lira had declined to 6.05 on Friday, its weakest point in regular trading since late May. It recovered briefly on Monday after the government imposed new limits on banks' foreign-exchange.
On the Istanbul stock market, the main BIST100 index was down 0.5% at 1020 GMT, while the banking index 1.61% lower. (Writing by Ali Kucukgocmen; Editing by Daren Butler and Jonathan Spicer)