One minute’s silence will be held later for the three victims of the Reading stabbing attack.
Teacher James Furlong, described as a “kind and gentle” man, was the first victim to be named publicly.
Meanwhile, police continue to question the suspect in Saturday’s attack, Khairi Saadallah, who has been arrested under the Terrorism Act.
Sources told the BBC he is originally from Libya and came to the attention of MI5 in 2019.
The second victim was Joe Ritchie-Bennett, his father has told US TV network CBS. It reported he was from Philadelphia but had lived in the UK for 15 years.
Robert Ritchie, told CBS the family was “heartbroken” and described his son as “brilliant and loving”.
A minute’s silence will be held at 10:00 BST for victims, according to the mayor of Reading, councillor David Stevens.
People are invited to join the silence via Reading Council’s Facebook page.
Reading Borough Council leader Jason Brock said the town was “an incredibly strong community” where “people will come together and they won’t allow themselves to be divided”.
Former pupils and current students of 36-year-old Mr Furlong, the head of history, government and politics at The Holt School in Wokingham who was killed in the attack, are also planning to light candles and lay flowers at a church near the school.
His parents Gary and Janet described their son as “beautiful, intelligent, honest and fun”.
“He was the best son, brother, uncle and partner you could wish for. We are thankful for the memories he gave us all,” they said in a statement. “We will never forget him and he will live in our hearts forever.”
One former pupil, Molly Collins, told BBC Radio 4’s Today programme he was a “passionate and enthusiastic” teacher who dedicated extra time to helping students progress.
“I wouldn’t have gone to university, I don’t think, had I not spoken about it with him. He just really took the time to support me and make me more confident,” she said.
Current pupils have also expressed their sadness at the news.
Sophie McEwan wrote on Instagram that Mr Furlong was “an inspirational teacher, [who] genuinely cared for all of us students”.
And Emily Mugnier wrote: “Thank you for being an incredible, enthusiastic teacher and lover of life.”
Co-head teachers at Mr Furlong’s school said he “truly inspired everyone he taught”.
Anne Kennedy and Katie Pearce said in a statement: “He was determined that our students would develop a critical awareness of global issues and in doing so, become active citizens and have a voice.”
Mr Furlong was one of three people who died in Saturday’s attack at Reading’s Forbury Gardens, which police were called to at about 19:00 BST.
Witnesses say a lone attacker with a knife shouted “unintelligible words” and stabbed several people who were in a group.
Security guard Sydney McDonald, 65, said he saw the suspect being rugby-tackled to the ground by police and arrested shortly after the incident.
“There was a guy and I saw him pointing to a man and saying ‘There he is, there he is’. If he hadn’t, they would have missed him. He was running really fast, properly fast.
“They put the emergency brakes on, jumped out of the car and rugby-tackled him to the floor.
“They put the handcuffs on, he wasn’t putting up a fight or anything like that, they picked him up and put him in the van, he just sat there all quiet, he wasn’t saying nothing.”
Three other people suffered serious injuries in the attack, but only one remains in hospital, where his condition is described as stable..
Mr Saadallah, 25, is from Reading and was arrested initially on suspicion of murder. He was later re-arrested on Sunday under Section 41 of the Terrorism Act 2000.
Under the Act, police have the power to detain him without charge for up to 14 days.
Police said they are not looking for anyone else in connection with the incident.
Sources told BBC’s home affairs correspondent Dominic Casciani that Mr Saadallah came to the attention of the security services after they received information he had aspirations to travel abroad – potentially for terrorism-related reasons.
However when the information was further investigated no genuine threat or immediate risk was identified, our correspondent said.
It meant that no case file was opened which would have made him a target for further investigation.
Sir Mark Rowley, a former national lead for counter-terrorism policing, told the BBC that MI5 has 3,000 people under investigation, but there are 40,000 who have “touched the system” at some point.
He said there were many volatile people who become interested in extremist ideology, but the security services faced a problem in identifying which of those would turn into an attacker.
In the last three years 25 terrorism plots in the UK have been disrupted, said Security Minister James Brokenshire.
He said the threat was “complex, diverse” and “rapidly changing” with hundreds of leads in any given week.
‘Learn from this’
Labour’s shadow home secretary Nick Thomas-Symonds said that with the Ministry of Justice’s budget having been cut by 40% over ten years, the government needed to re-examine the resources available for de-radicalisation programmes in prisons, as well as monitoring, supervision and risk assessment of released prisoners.
Boris Johnson has held a meeting with security officials, police and senior ministers over the incident in Reading, and the PM has promised action “if there are lessons that we need to learn”.
Labour leader Sir Keir Starmer has said that “people are united in their grief” following the attack, and that he wants to speak to the prime minister to discuss how to “learn from this”.