Over the course of three days, Christian militias on one hand and Lebanese Leftist and Palestinian militias on the other clashed in various parts of the country.

In Beirut, fighting broke out in areas where there was some proximity between Christian-populated residential areas and Palestinian camps or Muslim-populated areas, which would later become regular conflict zones: Dekwaneh-Tel al-Zaatar, Ain al-Remmaneh, Chiyah, Haret Hreik, Mreijeh, Burj al-Barajneh, Karantina, Maslakh, and Ashrafieh. Weapons included rocket launchers, automatic rifles, and mortars of small caliber. Clashes also broke out in North Lebanon between Tripoli and Zgharta. In the Shuf, Palestinian commandos from the Barja region attacked two neighboring Christian villages (Ain al-Assad and Marj Barja), causing a temporary displacement of population toward the Christian-populated East Beirut. And in Saida a general strike was ongoing, with continuous explosions and gunfire.

During this time, according to newspaper reports, 300 people were killed, 1,500 buildings destroyed, and losses amounting to $200 million were reported by the Chamber of Commerce and Industry.

Mahmud Riad, the secretary general of the League of Arab States, landed in Beirut on April 14 and announced a ceasefire on April 16. The Kataeb, the PLO, the National Movement (NM), and the PNL agreed to retract their armed members from the streets. The Kataeb handed over two of the seven party members who were accused of the bus shooting. The ceasefire remained shaky, however, because various incidents of abductions, explosions, and clashes were still taking place across the country.