Heavy machine gun fire and the sound of mortar bombs has been heard along the Turkey-Syrian border near the Syrian town of Haram, according to a Reuters witness.
It was not clear whether the firing was from the Syrian army or from rebels fighting to overthrow President Bashar al-Assad.
The firing could be heard from the Turkish border village of Besaslan in southern Hatay province.
More top news
Colder but clear this evening
Two teenagers found dead at the foot of a sheer drop at Huntcliff have been named as 17-year-olds Alex Yeoman and Harry Watson.
Violet Grace Youens died in hospital a day after she was struck in a suspected hit and run as she walked with her grandmother in Merseyside.