even more violence especially with isis posting announcements like this one online. we will go to iraq in a few days and we will fight and come back and we will even go to jordan and lebanon with no problems. reporter: worry here is growing. i m really very concerned because for the simple reason that the stability and lebanon is very fragile. reporter: analysts say lebanle isis could weaken security forces and deepen sectarian forces. a rising tide of sunni anger toward shiite military group hezbollah has been to blame for several car bombs targeting shia-populated areas around beirut. now blood is being shed once more and many suspect isis is behind it. on friday, a car bomb targeted a security checkpoint in the baqa valley. another worrying sign.