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, whose volatility has spiked since a late Friday selloff, weakened as far as 6.0500 against the dollar from a close of 6.0075 on Monday. It stood at 6.0305 at 1305 GMT.

Worries over Turkey's increased military involvement in Syria have been growing, said Jason Tuvey, senior emerging markets economist at Capital Economics.

A London forex trader said local banks had continued to sell dollars on Monday around the 6.02 level albeit at smaller volumes than last week.

The lira also 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 BIST 100 index was up 0.86% at 1234 GMT, while the banking index was 0.12% lower.