A video has gone viral showing an activist being arrested while speaking to reporters at a Black Lives Matter protest.

The unnamed protester was one of 74 detained in Rochester in western New York State.

The protest was held in the wake of the fatal shooting of 37-year-old Alton Sterling by police in Baton Rouge, Louisiana.

She told reporters, "We don't need this exact format, we need us to come out in numbers, we need more Rochesters," before she was surrounded, arrested and led away.

As a result, the nearby crowd angrily started chanting: "No justice, no peace."

TWC News reporter Tara Grimes, who took the now viral video, subsequently released footage of the female protester questioning the attending police officers in their riot gear.

While standing in the middle of the street, which had been cleared of protesters, she shouted: "I need answers, There are so many cops out here but but zero answers.

"What do you want from us? What do you expect from us? Are we boring you? Is it boring?

"So you're onto the next guy you pull over that you're so shaken in yourself that you have shoot their bodies six times."

It is not known why she was arrested but she was released from custody the next day.

Included in those arrested were two black journalists who were covering the event for ABC TV news.

They were present when police began to clear a street of protesters but no other journalists, photographers or onlookers at the scene were detained by police.

Reporters Justin Carter and Carlet Cleare later received personal apologies from the City's Mayor and Rochester Police Department Chief Michael Ciminelli who said: "Two local reporters, Carlet Cleare and Justin Carter, were taken into custody at the scene.

"I apologize for that. They were there trying to do their job covering this event."

According to Chief Ciminelli, there had been more than 400 people at the protest and that the 74 were arrested for disorderly conduct.

While he said he could not go into details of each of the arrests, he did stress that the department "didn't blindly make arrests".

Chief Ciminelli added that the officers only started wearing riot gear after rocks had allegedly been thrown at them.

On the same night, over 30 people were arrested in Baton Rouge at another Black Lives Matter protest.