Three Syrian Islamist opposition groups, including Al-Qaeda affiliate Al-Nusra Front, were battling for control of a regime-held border crossing with Turkey on Friday, a monitoring group said.
"Al-Nusra Front, Sham al-Islam and Ansar al-Sham are engaged in fierce clashes around the Kasab crossing with Turkey in Latakia province," Syrian Observatory for Human Rights director Rami Abdel Rahman told AFP.
"They have seized guard posts around the crossing but are not yet in control of it," he said.
Syrian state television made reference to the fighting in a breaking news alert, saying the army was "tackling attempts by terrorist gangs to infiltrate from Turkish territory and attack border crossings in northern Latakia province."
The alert, citing a military source, said 17 opposition fighters had been killed and "many others" wounded in the fighting.
The Observatory gave no immediate toll from the fighting.
The clashes there came after the three Islamist groups announced the beginning of the "Anfal" campaign in the Latakia area.
Al-Nusra is the Syrian affiliate of Al-Qaeda and one of a number of jihadist groups fighting to overthrow President Bashar al-Assad.
Large parts of Latakia province have remained relatively insulated from the fighting elsewhere in Syria.
The province, which includes Assad's ancestral village, is considered a stronghold for the regime, and many of its residents are from the Alawite minority, like Assad.