A teenage actor was charged with 'creating a public nuisance' after he was seen covered in blood while holding a firearm last night on a bridge in Brisbane's CBD.

The 18-year-old actor was reportedly first seen on the William Jolly Bridge about 5:30 pm and called triple-zero.

In a statement, the police said that the teenager was 'in possession of a replica semi-automatic weapon.' It was soon discovered that the teenager was a university student, and was participating in making a short film. The Sandgate actor was served notice to appear befor the Brisbane Magistrates Court this month for creating a public nuisance.