Condoling the losses of lives in the tragedy, US Vice President Mike Pence tweeted: "@POTUS & I are closely monitoring the attack on innocent people in Toronto this afternoon. We are with the Canadian people tonight as they grieve the loss of life & injured. The American people stand shoulder-to-shoulder with our neighbors in Canada."

White House Press Secretary Sarah Huckabee Sanders said in a statement: "The United States stands with the Canadian people in the aftermath of today’s tragic event in Toronto, where a van drove into a crowd of people killing several and injuring many more.  Our thoughts and prayers go out to the families of those affected, and we wish a full recovery to those injured.  The United States Government pledges to provide any support Canada may need."

New York Mayor Bill de Blasio also joined others in condoling the loss of lives in the attack when he tweeted: "Our prayers are with the victims of today's horrific van attack in Toronto. We extend our deepest condolences to their families and loved ones. "

At least 10 people were killed when a white van in Canadian city of Toronto mounted the kerb and struck several pedestrians on Monday, the police said.

The incident left 15 others injured.

"On Monday, April 23, 2018, at about 1:30 p.m., police were called to a collision in the area of Yonge Street and Finch Avenue East. It was reported that a van had mounted the curb and a number of pedestrians had been struck," the Toronto Police said in a statement.

The police said they have arrested one person in connection with the incident so far. The van involved in the incident has been seized.

The arrested person has been identified as Alek Minassian.

Toronto City police chief Mark Saunders has said that the incident seemed to be deliberate but the motive of the attack was still not known.

"The actions definitely look deliberate,” Chief Saunders was quoted as saying by TPS News.

He urged witnesses to come forward and help the police in carrying out the investigation.

"We’re still looking for more witnesses,” he said.

Urging people to share information with them, he said: "You may have a piece of the puzzle.”

He said the police is working hard to understand the exact motive behind the attack.

“We’re looking strongly at the exact motive," he said.