According to authorities, four members of a Canadian Muslim family were intentionally targeted in an anti-Islamic hate crime when a pickup vehicle hopped the curb and ran them down.

“There is evidence that this was a planned, pre-meditated act, motivated by hate,” London Detective Superintendent Paul Waight said on Monday, providing no further details.

Canadian Prime Minister Justin Trudeau described the attack as “hateful and heinous” on Twitter.

“It is believed that these victims were targeted because they were Muslim,” Mr Waight said.

Police arrested the suspected attacker, 20-year-old Nathaniel Veltman, on Sunday.

He was described as a resident of London, Ontario. He was charged with four counts of first degree murder, and one count of attempted murder.

Police said the family has requested that the names of the victims not be released yet, but they did provide their ages.

A 74-year woman died on the scene, a 46-year-old male, a 44-year-old female and a 15-year-old female died after being taken to the hospital, police said. A nine-year-old boy survived and is in the hospital with serious injuries.

“We grieve for the family, three generations of whom are now deceased,” London’s Mayor Ed Holder said at a virtual press conference held jointly with police.

“This was an act of mass murder, perpetrated against Muslims, against Londoners, and rooted in unspeakable hatred.”

Mr Waight said police in London, about 200 kilometres southwest of Toronto, were liaising with the Royal Mounted Canadian Police on potentially filing terrorism charges.

The attack was the worst against Canadian Muslims since a man gunned down six members of a Quebec City mosque in 2017.