PARIS — The Paris prosecutor's office opened an investigation Sunday regarding a protest around the American Embassy that drew hundreds of people angry over of a film produced in the United States that insults the Prophet Muhammad.

In the wake of Saturday's unauthorized protest, uniformed and plain clothes police were added to the streets surrounding the embassy, police officer Pierre Coric said. Police detained 150 people as they broke up the demonstration; one was still in custody Sunday for roughing up an officer.

Between 200 and 250 people converged Saturday afternoon on the streets around the embassy, which is not far from the famed Champs-Elysees Avenue and France's presidential Elysee Palace. They were apparently responding to calls put out via text message and social media.

The prosecutor's office will look into how such a large demonstration was organized without the proper permits, according to spokeswoman Agnes Thibault Lecuivre.

Interior Minister Manuel Valls has called the protest, which at one point saw dozens of men praying on the sidewalks, "unacceptable."

The demonstration was part of a wave of protests outside U.S. diplomatic posts around the world, some of which have turned violent. The U.S. Ambassador to Libya was killed during an attack on the consulate in Benghazi; protesters have also stormed the U.S. Embassy in Tunis and held violent demonstrations outside posts in Egypt and Sudan.