The ongoing protest in front of Toronto police headquarters expanded on Saturday — closing off College Street for much of the day as demonstrators continued to call for charges against the police officer who shot and killed Andrew Loku.

The protesters, who have been camped outside of police headquarters for almost a week, also got a show of support today from CUPE.

Members of the union, including president Fred Hahn, joined the Black Lives Matter demonstration in what Hahn described as a show of "solidarity against oppression."

"Black CUPE members face anti-black racism every day," he said in a statement.

The protest got bigger and louder on Saturday — turning to something of a street party by evening.

Black Lives Matter protesters dance and chant outside Toronto police headquarters 0:31

Yo. It's a free concert. <a href="https://twitter.com/hashtag/BlackCity?src=hash">#BlackCity</a><a href="https://twitter.com/hashtag/BLMTOtentcity?src=hash">#BLMTOtentcity</a> <a href="https://twitter.com/hashtag/BLMTOblackout?src=hash">#BLMTOblackout</a> <a href="https://t.co/QRIdu4r36W">pic.twitter.com/QRIdu4r36W</a> —@camilacore

Demonstrators have been outside police headquarters since Ontario's Special Investigations Unit said it would not lay charges against the Toronto police officer who shot and killed Loku, a 45-year-old immigrant from South Sudan, in July 2015.

Protesters say what happened to Loku is a symptom of systemic racism.

"I'm a lawyer, but folks don't see that. Before anything, they see a young black man," said Anthony Morgan of the African Canadian Legal Clinic.

Morgan says he hears complaints every day from people about their interactions with police.

Other activist groups expressed their support for the ongoing Black Lives Matter protest outside police headquarters. (CBC)

But tracking the issue is difficult because the exact number of interactions between police and visible minorities is not made public in Canada.

"We understand that they have a challenging job but … we are confident that job can be rendered more effective if we have more systemic ways of collecting the data," Morgan said.

Black Lives Matter has called for the officer who shot Loku to be identified and charged.

"We know that we're disproportionately targeted. You can hear it from our stories, from our lived experiences," said Pascale Diverlus of the group's Toronto chapter.

By evening College Street had reopened to traffic and DJs and rappers were performing for the crowd from the back of a flatbed truck.

Amazing energy at <a href="https://twitter.com/hashtag/BLMTOtentcity?src=hash">#BLMTOtentcity</a> this afternoon <a href="https://twitter.com/hashtag/BlackLivesMatter?src=hash">#BlackLivesMatter</a> <a href="https://twitter.com/hashtag/NoJusticeNoPeace?src=hash">#NoJusticeNoPeace</a> <a href="https://twitter.com/BLM_TO">@BLM_TO</a> <a href="https://t.co/aMOAMfTjuj">pic.twitter.com/aMOAMfTjuj</a> —@SheilaMatthen