A group of 50 professors signed a letter urging Rhode Island lawmakers not to ban indoor prostitution.

Rhode Island is the only state in the country besides several counties in Nevada where indoor prostitution is legal. Prostitutes and their customers who operate outside can still be prosecuted.

In a letter issued Saturday, George Washington University professor Ronald Weitzer and Nassau Community College professor Elizabeth Wood said prostitutes who work indoors are less likely to be assaulted, raped or robbed.

They said treating indoor and outdoor prostitution differently is a step in the right direction.

House and Senate lawmakers have backed sharply different bills that would ban indoor prostitution. They are trying to reach a compromise before a vote expected in September.