Delgado won a 2003 Billboard Latin Music Award for rap album of the year as part of the duo "Los Bambinos" and he has collaborated with hip-hop artist Jay-Z.
The confrontation occurred before dawn when Delgado stopped at a gas station to buy food after playing at a private party.
When a 26-year-old woman insisted on having his autograph, someone in Delgado's group grabbed her. An argument broke out when the fan's husband approached, and someone fired a gun several times in the air, police spokeswoman Maria del Pilar Bon said.
At one point, someone bit the woman's right arm, Bon said, adding that she did not know how serious the bite was.
Police were investigating who fired the shots, but said it was someone in Delgado's group, police officer Yolanda Hernandez said.
Delgado's group fled without paying for their gas. They were detained later at another gas station in western Puerto Rico, Bon said.
Delgado, a performer who has promoted other prominent artists, apologized for being linked to the confrontation but declined to comment or provide details.
"I would never deny a fan my autograph," he said. "I have always been known for being a humble person who gives his all to the public, since the public helps bring a plate of food to my house."
