The 1978 South Lebanon conflict (code-named Operation Litani by Israel) was an invasion of Lebanon up to the Litani River, carried out by the Israel Defense Forces in 1978 in response to the Coastal Road massacre. The conflict resulted in the deaths of 1,100–2,000 Lebanese and Palestinians, 20 Israelis, the internal displacement of 100,000 to 250,000 people in Lebanon, and the PLO forces retreating north of the Litani River. It led to the creation of the UNIFIL peacekeeping force and an almost complete Israeli withdrawal.