The officers in Baton Rouge were responding to reports of a man carrying a gun on Sunday when shots were fired at around 9am local time. Two Baton Rouge police officers and a sheriff’s deputy were killed.

The gunman, identified by a US official as 29-year-old Gavin Long from Kansas City, Missouri, was killed in a shootout with police a short time after he opened fire on the first group of officers. Police have also arrested two people they believe are linked to the shooting.

President Barack Obama has condemned the attack and vowed that justice would be done.

“We may not yet know the motives for this attack, but I want to be clear: There is no justification for violence against law enforcement. None. These attacks are the work of cowards who speak for no one,” he said in a statement.

It has been revealed that just days before he was shot and killed, one of the Baton Rouge police officers posted an emotional Facebook message saying he was “physically and emotionally” tired from being both a police officer and a black man.

“I swear to God I love this city but I wonder if this city loves me,” Montrell Jackson wrote.

In post, Jackson said while in uniform he got nasty looks and out of uniform some considered him a threat.

“I’ve experienced so much in my short life and these last 3 days have tested me to the core,” the post read.

“These are trying times. Please don’t let hate infect your heart.”

Friends and family of Jackson are mourning the 10-year-veteran of the police force, who relatives described as a “gentle giant” and a “protector”.

Lonnie Jordan, Jackson’s father-in-law, described his son-in-law as a “gentle giant” – tall and stout and formidable looking, but with a peaceful disposition, saying he was “always about peace.”

Louisiana Governor John Bel Edwards called the shooting an “unspeakable, heinous attack”.

“There simply is no place for more violence. That doesn’t help anyone, it doesn’t further the conversation, it doesn’t address any injustice, perceived or real. It is just an injustice in and of itself,” he said in the press conference.

The Black Lives Matter civil rights movement has called for police to end racial profiling, bringing the issue to national attention ahead of the November 8 US presidential election.

It is a time of especially heightened security across the country, notably in Cleveland and Philadelphia, hosts to this week’s Republican National Convention and next week’s Democratic National Convention, respectively, which are expected to formally nominate Donald Trump and Hillary Clinton for the election.

Trump said “We demand law and order,” in a Facebook post on Sunday afternoon.

The head of a Cleveland police union has called on Ohio Governor John Kasich to declare a state of emergency and suspend laws allowing for the open carry of firearms during the Republican convention.

A witness to Sunday’s shootings, Brady Vancel, told a CBS television affiliate he had seen a gunman, a second man in a red shirt lying in a parking lot and another gunman running away “as shots were being fired back and forth from several guns.”

-Reuters