Prior to the attack Attack , Camille Chamoun decided Deciding to disarm the militia in order to avoid Preventing_or_letting further bloodshed from both the Phalangists and the Tigers .

On 6 December 1975 , a Saturday , four young Christian Phalangists were assassinated Killing on the Fanar ( Matn ) road in Beirut .

In retaliation , Phalangists murdered Committing_crime hundreds of non-Christians .

It was wrongly assumed Choosing by the Phalangists that Palestinian militants had carried out Action the assassination .

Various forces — Israeli , Phalangists and possibly also the South Lebanon Army ( SLA ) — were in the vicinity of Sabra and Shatila at the time of the slaughter , taking Action advantage of the fact that the Multinational Force had removed Removing barracks and mines that had encircled Attack Beirut 's predominantly Muslim neighborhoods and kept Temporary_stay the Israelis at bay during the Beirut siege .

The Israeli Army surrounded Surrounding Sabra and Shatila and stationed Motion troops at the exits of the area to prevent Preventing_or_letting camp residents from leaving Departing and , at the Phalangists ' request Request , fired Use_firearm illuminating flares at night .