Security forces fired tear gas and water cannon to force back flag-waving protesters close to the embassy complex north of the capital, Beirut.
Overnight the Arab League condemned the US decision. It said the US could no longer be relied on as a broker of peace in the Middle East.
Turkish president Recep Erdogan reportedly referred to Israel as a "terrorist state" that "kills children" in an address in the central city of Sivas.
Meanwhile a 24-year-old Palestinian man has been arrested after stabbing an Israeli police officer in Jerusalem. The victim is said to be in a "serious condition".
Israel says it has targeted sites in Gaza belonging to militant group Hamas in retaliation over an attack. Israeli military said it hit weapons sites early on Saturday morning.
Two people were killed in the strikes, according to local reports, bringing the deaths in Israeli strikes and gunfire over the past few days to four.