In the first shooting, two gunmen, who have not been identified yet, started shooting at people near a basketball court in Little River Park on Sunday, injuring eight people, Xinhua news agency quoted an NBC News report as saying.
The report said that of the eight, six people were in serious condition.
The second incident occurred in the Allapattah neighbourhood, during which four people were injured, the police said.
The victims have been taken to a local hospital and are currently in stable condition, the police added.
“This type of gun violence has to end,” the NBC News report quoted Alfredo Ramirez, Director of the Miami-Dade County Police Department, as saying at a briefing on Sunday night.
“We must work together as a community,” he added.
The authorities have not declared whether the two shootings were related.
An investigation is underway.