At least three people, including a suspected gunman, have been shot dead in the US state of Colorado, police said at a press briefing.
A 19-year police officer was killed in the incident along with another person in Arvada, a Denver suburb on Monday before the perpetrator was fatally shot by police.
The authorities said the individual shot by the suspect was transferred to a local hospital where he later died. The identities of the shooter and the other victim have yet to be revealed.
The slain officer, confirmed as Gordon Beesley, responded to a call about a suspicious occurrence near a library in Arvada. Minutes later, a 911 call came in regarding shots fired and the officer being hit.
Beesley worked as a school resource officer at the local Oberon Middle School, and worked in the patrol division as school was out for the summer.
The Arvada officer is the second Colorado policeman to die this year while responding to a shooting.
Officer Eric Talley of the Boulder Police Department died on 22 March while responding to a mass shooting at a local grocery store. 10 people lost their lives in the attack.
At least three other cops in Colorado have been shot and survived while responding to events this year.
According to local reporters, after the shooting, a detachment of police bomb squads was deployed to the site of the attack.
Gun violence claims the lives of nearly 40,000 people each year across the US.
Earlier this month, at least eight Americans were killed as an employee of the Valley Transportation Authority opened fire on people at a rail yard serving Santa Clara County, California.
In the wake of the tragic incident, President Joe Biden called on Congress to implement measures to end what he called “epidemic of gun violence.”
The president issued a one-word plea: "Enough," saying that Congress should immediately "heed the call of the American people, including the vast majority of gun owners, to help end this epidemic of gun violence in America."
“We are resolved to bring meaning to this tragic moment with real action to curb the gun violence crisis in our country,” he said.
The US president said that authorities “must address the root causes of these devastating acts at every level of government.”
The Colorado shooting became the latest in a series of major gun violence incidents this year, some of which took place just days apart, including in George, Colorado, South Carolina and Indiana.
Over four weeks in March and April, the US saw three such shootings that involved mass casualties.
Eight were killed, including six women of Asian descent, at Atlanta-area spas in mid-March.
Less than a week later, 10 were killed at a supermarket shooting in Colorado and a few weeks after that, eight were killed at a FedEx facility in Indianapolis.
In recent years, the US Democrats have called for universal background checks as well as a ban on military-style “assault” weapons, but conservatives remain steadfastly against strict, new gun control
During his presidential campaign, Biden pledged to reinstate an assault weapons ban, create a voluntary gun buyback program and send a bill to Congress to repeal liability protections for gun manufacturers and close background check loopholes.
With about 121 firearms in circulation for every 100 residents, the US is by far the most heavily armed society in the world, according to the Geneva-based Small Arms Survey, a research group.