At least four people have been killed and 18 others have been injured in a mass shooting in Birmingham, Alabama, according to police.

“Multiple shooters fired multiple shots on a group of people” late Saturday in the Five Points South area, reported Birmingham police officer Truman Fitzgerald.

Authorities discovered the bodies of two men and one woman at the scene, while a third man later succumbed to his injuries in the hospital, Birmingham Police confirmed.

Detectives are looking into whether the shooters approached the victims on foot or from a vehicle, Fitzgerald stated. No suspects have been apprehended.

He mentioned that the shooting was believed to be "not random and stemmed from an isolated incident where multiple victims were caught in the crossfire."

Detectives are also trying to determine who the intended target or targets of the attack were, Fitzgerald added.

They are actively seeking the shooters. The police released a statement indicating they are collaborating with the FBI and other federal agencies, offering a $5,000 reward for information as they set up a web portal for submitting photos and videos related to the incident.

The shooting took place in the Five Points South district, an area known for its nightlife, specifically on Magnolia Avenue, according to Fitzgerald.

Witnesses from nearby areas reported to local news site Al.com that some of the gunfire sounded like it came from a fully automatic weapon.

Earlier on Sunday, Fitzgerald informed reporters there were "dozens of gunshot victims" after the shooting.

Birmingham Mayor Randall Woodfin attributed the violence to "Glock switches"—devices that can modify handguns to fire automatically. He posted on social media Sunday that these switches "are the number one public safety issue in our city and state."

"Converting a semi-automatic weapon into a fully automatic weapon that discharges all bullets within seconds doesn’t belong on our domestic streets," he stated, adding that the city lacks the authority to ban Glock switches, which is a matter for the state.

US gun violence: Debate intensifies as firearm deaths soar

Gun violence is a frequent issue in the United States, where there are more firearms than people. Despite public opinion polls showing a desire for stricter gun regulations, the strong influence of the gun rights lobby, constitutional protections, and a deeply ingrained gun culture create significant political obstacles to enacting tighter controls.

The 2022 gun safety legislation passed by Congress was the most significant in decades, enhancing background checks and supporting states with "Red Flag" laws that allow the confiscation of weapons from individuals deemed high-risk. Nevertheless, advocates argue that more comprehensive measures are necessary.

In that same year, over 48,000 people died from gun-related incidents, prompting the surgeon general to issue a landmark advisory declaring gun violence a "public health crisis."

Gun rights and gun violence are key issues in elections. Republican candidate Donald Trump, viewed as a strong supporter of gun rights, expressed on social media that "our hearts are with the victims" of the Georgia shooting.

On the other hand, Democratic nominee Kamala Harris, a former prosecutor, attorney general of California, and US senator, urged Congress to "finally" pass an assault weapons ban. This proposed ban would mirror the one that President Joe Biden helped draft and pass into law in 1994, which expired after a decade without renewal by Congress.