A film produced in the United States viewed as insulting to the Islamic Prophet Muhammad sparked global outrage against U.S. interests.
The FBI sent agents to Libya to investigate the circumstances surrounding the Sept. 11 attack on the U.S. consulate, which left the U.S. envoy to Libya and three staff members dead. It was unclear whether the attack was linked to the film or a previously planned terrorist attack.
The U.S. government had said it considered the attack an act of terrorism but added it didn't have evidence yet to suggest it was a premeditated assault.
Arab League Secretary-General Nabil el-Araby said in a statement alongside U.S. Secretary of State Hillary Clinton that further measures should be taken to prevent violence like that which was associated with the controversial film.
"We all should work on further measures to ensure that such events will never happen (again)," he said.
A statement issued last week by the Arab League, the Organization of Islamic Cooperation and the European Union said "offensive speech cannot be met with violent acts as it will only create a spiral of brutality from which we will all suffer."
The U.S. Embassy in Bangkok issued a statement Wednesday advising U.S. citizens in Thailand that protests are planned in front of the embassy grounds this week.