Prime Minister Justin Trudeau said on Sunday he was "heartbroken" after learning that a Canadian was among the seven killed in Saturday's attack in London.

Christine Archibald, 30, from Castlegar, B.C., had moved to Europe to be with her fiancé, a statement from Archibald's family said.

Global Affairs Canada confirmed Sunday that she was one of the victims after men using a van and knives killed seven people and injured dozens more on London Bridge and in the nearby Borough Market.

"Canada strongly condemns the senseless attack that took place last night in London, United Kingdom, which killed and injured many innocent people. I am heartbroken that a Canadian is among those killed," Trudeau said in a statement.

'Canadians stand united in sending our love and support to our friends in London. We stand with you all,' Prime Minister Justin Trudeau said during the national Press Gallery dinner on Saturday night. (Fred Chartrand/Canadian Press)

"We grieve with the families and friends of those who have lost loved ones, and wish all those injured a speedy and full recovery.

"Londoners and people across the United Kingdom have always displayed strength and resilience in the face of adversity. We recently witnessed this after the attacks in Manchester and in the Westminster area of London. This time will be no different.

"These hateful acts do not deter us; they only strengthen our resolve. Canadians stand united with the British people. We will continue to work together with the United Kingdom and all our allies to fight terrorism and bring perpetrators to justice," Trudeau said.

Horrified by the events in London this evening. Canada will always stand by the people of London and is ready to provide assistance. <a href="https://t.co/7e7ZEJYHJy">https://t.co/7e7ZEJYHJy</a> —@AndrewScheer

Conservative Leader Andrew Scheer tweeted that he was "horrified by the events in London" and that Canada would always stand with the people of London. He later released a full statement.

"We must not allow random acts of terror to become the new normal," Scheer said. "I do not want to see my children grow up in a world where they are afraid to go to the mall, or a concert, or travel the world. This is why Canada, and our allies, must be fully committed to confronting and destroying this terrorist threat."

Earlier, the federal government advised Canadians to be vigilant in the wake of Saturday night's deadly terror attacks.

The government and diplomats on the ground in London advised travellers to avoid the affected areas, follow the instructions of local authorities and to monitor local media.

Trudeau called news of the attack "awful" in a tweet Saturday night. He later made a brief statement at the National Press Gallery dinner in Gatineau, Que.

'Beautiful, loving daughter and sister'

In a statement, the Archibald family lauded Christine's compassion for others.

"We grieve the loss of our beautiful, loving daughter and sister. She had room in her heart for everyone and believed strongly that every person was to be valued and respected," the statement reads.

Christine Archibald with her fiancé, Tyler Ferguson. (Mark Ferguson/Facebook)

"She lived this belief, working in a shelter for the homeless until she moved to Europe to be with her fiancé. She would have had no understanding of the callous cruelty that caused her death."

The carnage began around 10 p.m. local time when police and witnesses said a white van barrelled into pedestrians on London Bridge.

Three men armed with large knives then fled the van and started attacking people at bars and restaurants in nearby Borough Market, home to many popular pubs and restaurants.

Police said seven people were killed and 48 others wounded, 21 of them critically, before officers shot and killed the three suspected assailants.

The violence turned a warm spring night in an area packed with revellers into a scene of panic and chaos, with officers running through crowded streets screaming for people to flee.