Four people were killed and 28 others injured during a shooting at a birthday party on Saturday night in Dadeville, Alabama, the Alabama Law Enforcement Agency said on Sunday.

There was no initial confirmation about what led to the shooting, and authorities have not confirmed whether a suspect is in custody.

One of the four people killed during the violence was a high school football player who was among those attending his sister's "Sweet 16" birthday celebration when a gunman opened fire.

The party was being held inside the Mahogany Masterpiece Dance Studio, converted from an old bank building located about half a block from city hall in Dadeville, a town of about 3,000 residents.

During two news conferences on Sunday, Sergeant Jeremy Burkett of the Alabama Law Enforcement Agency did not take questions or provide the names of those killed.

"We're going to continue to work in a very methodical way to go through this scene, to look at the facts, and ensure that justice is brought to bear for the families," he said.

U.S. President Joe Biden was briefed on the shooting, the White House said, adding that it is closely monitoring the situation and has been in touch with local officials and law enforcement to offer support. 

"What has our nation come to when children cannot attend a birthday party without fear? When parents have to worry every time their kids walk out the door to school, to the movie theater, or to the park?" Biden said in a statement on Sunday.

Dadeville Mayor Frank Goodman said guns and violence are not common in Dadeville, adding that trying to control guns would prove as futile as trying to control illegal drugs.

The Gun Violence Archive, a Washington D.C.-based organization that monitors gun violence in the U.S., has recorded 163 mass shootings in the country so far this year, including 16 incidents in the week from April 10 to 16.

The year 2023 witnessed the most mass shootings and mass shooting deaths at this time in the year in at least a decade.

Noting that guns are the leading killer of children in the U.S., and the numbers are rising, Biden called on Congress to "require safe storage of firearms, require background checks for all gun sales, eliminate gun manufacturers' immunity from liability, and ban assault weapons and high-capacity magazines."

(With input from agencies)