On 11 March 1978, Palestine Liberation Organization (PLO) operatives, led by Dalal Mugrabi, carried out the Coastal Road massacre within Israel which resulted in the deaths of 37 Israelis, including 13 children, and 76 wounded.

Starting on the night of 14–15 March and culminating a few days later, Israel Defense Forces (IDF) troops occupied the entire southern part of the country except for the city of Tyre and its surrounding area.

On 15 March 1978 the Lebanese government submitted a strong protest to the United Nations Security Council against the Israeli invasion, stating that it had no connection with the Palestinian operation.

On 19 March 1978 the U.N. Security Council adopted Resolution 425, in which it called upon Israel to cease immediately its military action and withdraw its forces from Lebanese territory.

The Security Council, Taking note of the letters from the Permanent Representative of Lebanon and from the Permanent Representative of Israel, Having heard the statement of the Permanent Representatives of Lebanon and Israel, Gravely concerned at the deterioration of the situation in the Middle East and its consequences to the maintenance of international peace, Convinced that the present situation impedes the achievement of a just peace in the Middle East, The first UNIFIL troops arrived in Lebanon on 23 March 1978, just four days after the resolution was passed, and Israel withdrew its forces by June 1978.