The assailant, 29, was subdued with a stun gun and arrested on suspicion of attempted murder at 7:14 p.m. Saturday in the suburb of Leytonstone, London's Metropolitan Police said.
Authorities later said that the suspect, Muhaydin Mire, of east London, had been charged with attempted murder. He's expected to appear in court on Monday.
Police had been dispatched to the station after receiving emergency calls reporting that a man had stabbed people and was threatening others, police said. The man threatened officers as they tried to reason with him, a statement said.
Police are looking into reports that the suspect yelled, "This is for Syria," during the attack, said Chioma Dijeh, a spokeswoman for the Metropolitan Police.
One man, 56, suffered serious knife injuries in the attack and was taken to an east London hospital, where he remains in a stable condition. His injuries are not considered life-threatening, police said.
A second man received a minor injury that did not require medical treatment, while a woman was also threatened by the suspect, police said.
Authorities initially said one person was seriously injured and two others lightly injured.
Cmdr. Richard Walton, head of the Metropolitan Police's Counter Terrorism Command, said police were investigating the stabbing as an act of terror.
"As a result of information received at the time from people who were at the scene, and subsequent investigations carried out by the Counter Terrorism Command ... I am treating this as a terrorist incident," he said in a statement.
He urged the public to "remain calm but alert and vigilant" in relation to any potential threat. "The threat from terrorism remains at severe, which means that a terrorist attack is highly likely."
Detectives searched a residential address in east London on Sunday afternoon as part of the investigation, police said.
Detective Superintendent Jacqueline Sebire of the local Waltham Forest police force praised the attending officers for "not only their bravery in confronting the man who was in possession of a knife, but also their quick response in providing first aid to the victim."
She appealed for anyone in the area at the time who may have seen something suspicious to call an anti-terror hotline.
Videos show arrest
In the wake of the stabbing, footage circulated widely on social media showing scenes from the bloody attack and its chaotic aftermath.
They show police confronting a man in the ticket area of the station, who is brandishing an object in his hand. The police yell: "Drop it! Right now!"
They fire a stun gun at the man, who continues pacing in front of the officers, then lunges at them, causing bystanders to back off in fear.
There is more shouting before a pop is heard, apparently from the stun gun, and the man falls to the ground. Someone watching shouts, "Yes! Stupid idiot!"
Two police officers roll the man onto his stomach and handcuff him.
A man in the crowd shouts, "You ain't no Muslim, bruv! You're no Muslim, bruv! You ain't no Muslim!"
The phrase was embraced by social media users
as a statement of defiance toward the attacker and his perceived motivations.
Sadiq Khan, a London member of Parliament and candidate for the city's forthcoming mayoral election, tweeted a picture of what appeared to be a London Underground information board: "London Underground say #youaintnomuslimbruv."
Jeremy Corbyn, the leader of the opposition Labour Party, tweeted that the attack was "absolutely shocking,"
while Tim Farron, leader of the Liberal Democrats, tweeted that it was "an act of pure evil by a psychopath on innocent people."
UK faces terror threat
The United Kingdom is facing stepped-up threats from ISIS
-- especially since British fighter planes began flying sorties last week against ISIS targets in Syria
. The strikes were launched after British lawmakers voted to extend their existing military efforts against the Islamist terror group in Iraq into Syria in the wake of the Paris attacks.