Shortly after midnight on Sunday (US time), a white Nissan Pathfinder pulled up to the El Mula Banquet Hall near Hialeah.
“The result is 20 to 25 victims with gunshot injury wounds, and two deceased on the scene.”
The wounded were taken to various hospitals in the area. At least one of those hospitalised is in critical condition, police said.
The banquet hall and billiards club had been rented out for a concert, Mr Ramirez said.
Angelica Green said both her son and her nephew were among those shot.
Her son was shot once in the abdomen area and is in stable condition after surgery, Ms Green said.
“However, my nephew was shot four times,” she said, including once in the abdomen area and three times in the leg.
Ms Green said her son is her only child.
“He’s not a statistic. He’s a graduate from college last year. So he’s educated. He was going out with his educated cousin to just celebrate the weekend, and they had not made it into the club as of yet,” she said.
“They said that some guys, three guys that they noticed … they just started shooting … for whatever reason, we don’t know.”
The Miami-Dade Police Department is asking anyone with information about the shooters or their whereabouts to contact authorities.
“These are cold blooded murderers that shot indiscriminately into a crowd and we will seek justice,” Mr Ramirez tweeted.
“My deepest condolences to the family of the victims.”
TV personality and Camping World CEO Marcus Lemonis is offering a US$100,000 reward for information leading to the arrest and conviction of those responsible for the mass shooting, the businessman tweeted.
On Friday, another shooting in the Miami area left at least one person dead and six others wounded.