Police are looking into a "mass casualty incident" after a driver plowed through a crowd celebrating a street festival in Vancouver, western Canada, killing a "number of people" on Saturday.

Police are yet to confirm the number of those who died or were injured, but said in a news conference that a 30-year-old man was arrested at the scene.

Vancouver's interim police chief Steve Rai would not give an update on the casualties, saying, in some cases, the victims' relatives still needed to be contacted.

Vancouver's 1130 NewsRadio cited a witness as saying they saw upward of 20 casualties.

Another witness told the broadcaster of screams as the driver of a black SUV plowed into the crowd, striking more than a dozen people.

Vancouver police said the incident happened shortly after 8 p.m. local time (0300 UTC/GMT) near East 41st Avenue and Fraser Street, in South Vancouver.

People gathered to celebrate Filipino festival and culture

The tragedy occurred on a day when people gathered at a neighbourhood party to celebrate Filipino culture.

The Lapu Lapu Day festival pays homage to Datu Lapu Lapu, who, in a battle in 1521, defeated Spanish colonial forces led by Portuguese explorer Ferdinand Magellan.

The festival organizers wrote on Instagram: "We are still finding the words to express the deep heartbreak brought on by this senseless tragedy. We are devastated for the families and victims."

The organizers earlier posted a video on Instagram to show people playing games at the neighborhood party.

Separately, a video posted to social media later showed victims and debris strewn across a long stretch of road, with at least seven people lying immobile on the ground.

A black SUV with a crumpled front section could be seen in still photos from the scene.

Driver arrested at scene

Police said in a statement on X that the driver was brought into custody.

A later police post described the suspect as a 30-year-old Vancouver man.

The Vancouver Sun newspaper cited sources as saying the driver appears to have been suffering from mental health issues. The paper said thousands of people were in attendance.

PM Carney says 'devastated' by news

Canadian Prime Minister Mark Carney said he was "devastated" to hear about the tragedy.

"I offer my deepest condolences to the loved ones of those killed and injured, to the Filipino Canadian community, and to everyone in Vancouver. We are all mourning with you. We are monitoring the situation closely, and thankful to our first responders for their swift action," Carney wrote on X.

Vancouver Mayor Ken Lim wrote on X: "I am shocked and deeply saddened by the horrific incident at today’s Lapu Lapu Day event. We will work to provide more information as soon as we can, but at this time."

"Our thoughts are with all those affected and with Vancouver’s Filipino community during this incredibly difficult time," Lim added.

The incident came just two days before Canada holds parliamentary elections.

This article first appeared on DW.

The Wire is now on WhatsApp. Follow our channel for sharp analysis and opinions on the latest developments.