Israel retaliated for the massacre by shelling four Lebanese villages , killing 20 people , injuring 40 , and spurring thousands of southern Lebanon 's residents to flee north . This in turn provided one of the motivations for the Dawson 's Field hijackings of 6 September 1970 . The IDF also began patrolling regularly inside southern Lebanon after the massacre
Dawson 's Field hijackings
Dawson's Field hijackings
Avivim school bus bombing