The first victim of the London attack was named last night as Canadian national Christine Archibald, who worked in a homeless shelter until she moved to Europe to be with her fiancé.
Seven people died and 48 people were injured, including 18 critically, in the attack at London Bridge and Borough Market in the city on Saturday night.
Ms Archibald's family said in a statement: "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.
"She would have had no understanding of the callous cruelty that caused her death."
According to his sister, Ms Archibald died in the arms of her fiancé, Tyler Ferguson.
Writing on Facebook, Cassie Ferguson Rowe said: "Last night in London my baby brother lost the love of his life on the London Bridge.
"In a split second his entire life was ripped away from him. Hearing his painful sobs on the phone while he's alone trying to deal with this tears me apart.
"I have no words. If you know Tyler, please be there for him now, and later when what happened sinks in, he's going to need us all."
Canadian Prime Minister Justin Trudeau said he was "heartbroken" to learn of Ms Archibald's death.
Applauding the UK for its strength and resilience in the face of adversity, he said: "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."
James McMullan, 32, from Hackney, is believed to have been another of the victims.
He was last seen outside the Barrowboy And Banker pub and his sister said police have told her his bank card was found on a body at the scene of the attack.
Melissa McMullan told Sky News: "While our pain will never diminish, it is important for us all to carry on with our lives in direct opposition to those who wish to destroy us and remember that hatred is the refuge of small-minded individuals and will only breed more.
"Words will never be able to match his essence, there will only ever be one James. Nowhere else will you find such humour and a unique personality, someone who puts friends and family above all others. He was an inspiration."
She added police told her they were unable to formally identify him until a coroner releases a report tomorrow.
