A play entitled "God is a gangster" will be performed under police protection in Romania after the theatre hosting it received threats, police said Friday.

The play, written by Canadian actor and playwright Nick Mancuso, since October has been periodically playing at a theatre in the western city of Timisoara, which recently received a letter threatening "merciless punishment" if it kept hosting it.

"Undercover police officers will be among the audience next Saturday and we will also have police officers in uniform in the area to be able to react fast if anything happens", Daniel Langa, the deputy police chief in the city, told journalists.

A few days before the letter, the representatives of all Christian denominations in Timisoara had asked the theatre to change the title of the play so as to respect Christian values in the predominantly Christian country.

The theatre's director, Ada Hausvater, told AFP she was "surprised" by the uproar, as the play has already been performed on seven occasions without any trouble since its premiere in October 2012.

Nick Mancuso said he was "disturbed to discover that there is a move in the church to censor" his play and the theatre hosting it.

"The story, which is inspired by the Book of Job, is the story of a homeless old tramp, who is dying from alcoholism, and is in his insane stupor convinced that he is God the Father," he said in a reaction sent by mail to journalists.

"Passersby are ignoring his existence and treat him (God) as though he were a gangster. Hence the title," he said.

Mancuso starred in the American TV series "Stingray" in the late 1980s and played several tough guy roles in Hollywood productions. He won a Canadian genie award in 1982 for his acting performance in "Ticket to Heaven".

"Certainly no offence was intended. It is a title, not a statement of fact", he said.

More than 97 percent of Romanians are Christian, with the vast majority -- some 86 percent -- belonging to the Orthodox Church, according to the last census.