For the purposes of investigating and prosecuting the offence provided for in article 431-10 of the Criminal Code, the judicial police officers mentioned in 2° to 4° of the article 16 of this code and, under the responsibility of the latter, the officers mentioned in the article 20 and in 1°, 1° bis and 1° ter of the article 21 may, on the written requisition of the public prosecutor, proceed at the scene of a demonstration on the public highway and its immediate surroundings to:
1° Visually inspecting people’s luggage and searching it, under the conditions set out in III of article 78-2-2;
2° The inspection of vehicles moving, stopped or parked on the public highway or in places accessible to the public, under the conditions set out in II of the same article 78-2-2.
The fact that the operations provided for in 1° and 2° of this article reveal other offences shall not constitute grounds for invalidity of the incidental proceedings.