MIAMI: Two people were killed and at least 20 injured Sunday when a gang of three shot indiscriminately into a crowd outside a concert in Miami, Florida, local police said.

The mass shooting happened during the early hours at a billiards hall on a commercial estate near Miami Gardens, to the northwest of the coastal city's downtown.

The venue was "hosting a scheduled event and several patrons were standing outside," Miami-Dade Police Department said in a statement.

When a Nissan Pathfinder SUV approached the scene, it added, "three subjects exited the vehicle and began shooting indiscriminately into the crowd."

The trio then got back in the car and fled the scene.

When first responders arrived, they found two people dead, according to the statement.

At least 20 injured people ended up in hospital, with at least one in a critical condition.

In a tweet, the department's director, Alfredo "Freddy" Ramirez III, condemned the "targeted and cowardly act of gun violence."

"These are cold blooded murderers that shot indiscriminately into a crowd and we will seek justice," he said.

The United States has a long and painful history of deadly gun violence, with a steady daily toll of shootings as well as high-profile mass killings that have targeted schools, work places and shopping centers.

Homicides, mostly gun-driven, have surged in the country over the past year.

Mass shootings have occurred in recent months at a FedEx facility in Indianapolis, an office building in California, a grocery store in Colorado and at several spas in Atlanta.

President Joe Biden last month branded US gun violence an "epidemic" and an "international embarrassment."

There were more than 43,000 gun-related deaths in the United States last year, including suicides, according to the Gun Violence Archive.