A 35-year-old man was killed in the southeastern Turkish town of Ceylanpinar early on Monday when a stray mortar shell fired across the border from Syria struck a house near the frontier, security sources said.
The shell was fired during clashes between Kurdish and Islamist fighters in the Syrian town of Ras al-Ain, the sources said. Five people have now been killed in Turkey in similar incidents since clashes began in the area in July.
Authorities closed schools in the town and warned locals not to leave their houses after the shell landed.
In October last year a shell fired from Syria hit the Turkish border town of Akcakale, killing five Turkish citizens.
Ethnic Kurds in Syria have a complex role in nearly three years of conflict that started when Syrian President Bashar al-Assad cracked down on a pro-democracy uprising.
The ensuing civil war has pitted Sunni Muslims against Assad's Alawite minority and different Kurdish militia have fought on both sides, normally over territory or power disputes.