LOS ANGELES, California (NYTIMES) - It was an entirely routine moment: Four people exited the home they had rented on Airbnb in Rialto, California, and loaded suitcases into their car.

Within minutes, several police cars had arrived and the group was being questioned as a helicopter flew overhead. A neighbour who did not recognise them had called the police, suspecting they were burglars.

They were in fact four creative professionals in town for an event. Now the three black people in the group are suing the Rialto Police Department, saying they were unfairly treated during the April 30 encounter.

"Got surrounded by the police for being black in a white neighbourhood," one of the guests, Donisha Prendergast, a filmmaker and a granddaughter of Bob Marley, wrote on Instagram.

"I'm sad and irritated to see that fear is still the first place police officers go in their pursuit to serve and protect, to the point that protocol supersedes their ability to have discernment."

"We have been dealing with different emotions and you want to laugh about this but it's not funny," Kelly Fyffe-Marshall, another filmmaker, wrote on Instagram.

"The trauma is real. I've been angry, frustrated and sad. This is insanity."

Komi-Oluwa Olafimihan, an artist, pointed out that "over 700 people that look just like me did not walk away alive from a situation like this last year."

The police and the renters offered different versions of events, but both recorded video: The police through their body cameras, the renters through their phones.

Fyffe-Marshall said the officers came out of their cars, demanding that the group put their hands in the air. At first, the renters "joked about the misunderstanding," she said, but the situation escalated after 20 minutes when a sergeant arrived.

The sergeant didn't know what Airbnb was, "insisted that we were lying about it and said we had to prove it," Fyffe-Marshall said. She showed the officers their booking confirmations and called the landlord, and the group was detained for 45 minutes, she said.

She said the neighbour called the police because they had failed to wave at her.

Fyffe-Marshall and Prendergast declined interview requests.

The Rialto Police Department said in a statement that the group was questioned for 22 minutes and that officers had not used restraints on them. The officers learned they were Airbnb guests "through reasonable inquiry," and they were "immediately released without incident," the police said.

"The Rialto Police Department is confident officers treated the involved individuals with dignity, respect and professionalism," the police said.

Many people of colour have reported that police have been called on them while going about their everyday business, a fact of life that has seen several prominent examples in recent weeks.

National outrage followed the arrest of two black men in a Philadelphia Starbucks; a group of black women had police called on them for golfing too slowly in York County, Pennsylvania; and two Native American brothers had a college visit in Colorado cut short when a parent told a 911 dispatcher that their behaviour and clothing was suspicious.

Airbnb has for years been battling concerns over discrimination - though its focus had been on those renting out their homes, not neighbours. The company brought on prominent advisers, including Eric Holder, the former US attorney-general, to help form new policies, and released a 32-page report in 2016 on how it planned to fight discrimination.

Airbnb said that what happened to the guests in Rialto was "unconscionable."

Laura W. Murphy, a senior adviser, and Janaye Ingram, the head of national partnerships, sent a letter to Rialto's police chief and mayor Monday (May 7) to request a meeting.

"We are deeply disturbed by the public reports suggesting that the police department's response was dictated by the guests' race," the two wrote.

"As African-American women who have seen the inequitable treatment of people of colour, we know that these kinds of incidents are often rooted in implicit and explicit bias. They are hurtful, discriminatory, traumatic and must end."