PARIS—American rapper Lil Baby was detained in Paris on Thursday for allegedly transporting drugs, according to the city prosecutor’s office. NBA star James Harden was also stopped but not detained, the prosecutor’s office said. Images shared on social networks showed the Brooklyn Nets star briefly frisked in the incident on one of the French capital’s most elite avenues. The prosecutor’s office said one other person was also detained, without releasing the identity. An investigation is under way. Harden and Lil Baby, whose real name is Dominique Jones, have been in Paris to attend fashion week, according to local media.