Police in Abbotsford, B.C. are being accused of using excessive force after cellphone video emerged this week of police firing non-lethal rounds at a homeless man.

The incident happened Tuesday afternoon, when staff at a local food bank staff called Abbotsford Police to say they felt threatened by a situation unfolding in the parking lot.

When police arrived, they found an agitated 57-year-old homeless man named Roy Roberts. Police say Roberts was seated on the ground next to a knife, but wasn't complying with their orders as they tried to arrest him.

Several police officers are seen in the video taken by a bystander ordering Roberts to lie face-down, mistakenly calling him “John,” with Roberts demanding to know what he’s done wrong.

Eventually, as Roberts rises to his feet, an officer pulls the trigger of a bean bag gun, sending Roberts to his knees in pain.

Pastor Ward Draper, the director of the 5 and 2 Ministries, is critical of the police response, accusing officers of escalating the situation.

“I don't know why the response was so big for someone so little in our community,” he told CTV News.

“…Maybe they did have a fear and maybe they were rightly founded. However, there are other tools available to address a situation like that besides turning a man’s legs into hamburger with those weapons.”

Draper says Roberts may have had a knife, as that's not uncommon for people who live on the street.

Roberts was taken to hospital for an assessment. He's also facing weapons charges.

Const. Ian MacDonald, of the Abbotsford Police Department is defending the officers’ handling of the situation, saying it needed to be dealt with quickly.

“Our top priority at that time was to take him into custody to make sure that knife doesn't get used on himself, doesn't get used on any officers, doesn't get used on any members of the public including those people who called 911,” he said.

The incident is just the latest involving homeless people in the City of Abbotsford. Homeless people there say they’ve been harassed for years, with their tents and structure regularly destroyed.

Last year, city officials were forced to apologize for dumping chicken manure on the grounds of a homeless camp in an effort to force the camp residents to move on.

Last month, a group representing homeless people in Abbotsford, B.C., announced they were suing the city, alleging that homeless people have suffered for years in the city and that the tactics used to harass them breach their Charter rights.

None of the allegations have been proven in court.

With a report from CTV British Columbia’s Norma Reid