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
The Labour leadership contender has vowed to renationalise Britain's railway network "line-by-line" if he becomes prime minister.
Two passenger trains have derailed while crossing a bridge in India, leaving at least 20 people dead and injuring hundreds more.
Actor Pierce Brosnan was stopped by airport security after trying to board a plane with a knife.