NEW : At least 14 people have been killed , an activist group says . Security forces clash with gunmen believed to be dissidents . The government blames the violence on a splinter faction of Al Qaeda in Yemen and accuses it of being behind last month's suicide bombing at a mosque that left more than 200 dead.
NEW : At least 14 people have been killed , an activist group says . Security forces clash with gunmen believed to be dissidents . Protests in Syria erupted seven months ago .