BEIRUT (Reuters) -Syrian troops exchanged fire with Lebanese soldiers and armed groups in northeast Lebanon overnight and into Monday in a new round of clashes along the border. The mountainous frontier has been a flashpoint in the three months since Islamist rebels toppled Syria's Bashar al-Assad,

Syrian and Lebanese troops exchanged fire along their shared border. Tensions have risen since Syrian rebels ousted Assad and formed a new army. Syria accused Hezbollah of involvement, but they denied it.