A float in Montreal's Fête nationale parade Saturday quickly prompted widespread rebuke online with some attendees calling it racist.

The float went along St-Denis Street carrying singer Annie Villeneuve and a pianist, along with a billboard that said "Once upon a time…" in French.

It was pushed by four black teens wearing tan-coloured clothes with dozens of white people following in white clothes.

A video of it was posted to Facebook around 2 p.m. ET and within three hours it had been shared more than 6,000 times.

The caption on the post says: "I'm not sure the organizers understand the concept of diversity."

The video posted to Facebook has been viewed nearly one million times. (CBC)

Organizers call race division random occurrence

The president of the organizing committee for the Montreal celebration, Maxime Laporte, said the float was being pushed by students from a local high school, Louis-Joseph-Papineau.

"We have people of all origins, Asian, African, from everywhere in the world who are Quebecers and participated in the parade," Laporte told Radio-Canada.

He went on to say they had partnered with the school's scholastic perseverance program and through it students volunteered to help in the day's events.

He said the reason they were labouring over the float is because the parade is eco-friendly, meaning all the floats are pushed by people.

He added it's completely random that black students were pushing the history float.

"I understand there's a controversy. I'd like to ask for calm," Laporte said.

Local high school eager to help

The students' coach, Sterve Lubin, said the school was eager to participate in the parade.

Sterve Lubin is a head coach in the athletics department at Louis-Joseph-Papineau High School. (Radio-Canada)

"I think it's a shame that people saw a colour and not the participants," Lubin said.

"It was a pleasure for us to be there. If we didn't want to be there, we wouldn't have been there."

Laporte added that organizers are doing everything to reflect diversity in how they plan the Fête nationale events.