A man recently released from prison after serving time for terrorism-related offenses strapped on a fake bomb and stabbed two people on a busy London street Sunday before being shot to death by police, officials said.
Deputy Assistant Commissioner Lucy D'Orsi said police are "confident" the attacker was 20-year-old Sudesh Amman. He had been convicted for publishing graphic terrorist videos online and had stockpiled instructions on bomb making and knife attacks, according to police.
"The suspect had been recently released from prison where he had been serving a sentence for Islamist-related terrorism offences," she said.
The afternoon incident in London recalled a November stabbing attack carried out by another man who had served prison time for terrorism offense. Two were killed in that attack.
Prime Minister Boris Johnson said measures will be introduced Monday to bring "fundamental" change to the way people convicted of terrorism offenses are handled in prison and afterward.
It seems likely the victims will survive Sunday's attack in the bustling commercial and residential south London neighborhood of Streatham, where Amman struck outside a major pharmacy on a busy shopping afternoon.
D'Orsi said a stabbing victim in his 40s thought to be in life-threatening condition has improved. She said the victim is no longer in danger and that a woman who had been hospitalized has been released.
One other female victim is still in the hospital with lesser injuries police believe were caused by flying glass after the attacker was shot dead.
D'Orsi said the incident started at 2 p.m. when Amman was already being trailed by police.
"Armed officers, who were part of a proactive counterterrorism operation and were following the suspect on foot, were in immediate attendance and shot a male suspect dead at the scene," she said.
She said police saw a device strapped to the attacker's body and called in specialist officers who quickly determined the purported explosive device was a hoax.
Officials praised the police action but questions are likely to be raised about why the officers trailing Amman could not prevent his attack.
Video from the scene appeared to show three undercover police officers in an unmarked car making a quick stop just after the attack.
Bell Reberio-Addy, a member of Parliament who represents Streatham, said the attacker had been under surveillance "for some time."
D'Orsi said there was no "continuing danger" to the public, but the area remained cordoned off as the investigation continued. The usually busy area was deserted as the public heeded police requests to stay away.
The drama about 5 miles (8 kilometers) south of central London marked a departure from recent terror attacks in the British capital that took place near landmarks such as London Bridge and the Houses of Parliament.
The attack caused chaos and panic on what had been a typical Sunday afternoon, with the streets filled wish shoppers.
Karker Tahir said he was at work when he saw police chasing a man down Streatham High Road, the area's main shopping district.
"They kept telling him, 'Stop! Stop!'' Tahir said. "But he didn't stop, and then I saw that they shot him three times. It was horrible seeing it. The man was on the floor and it looked like he had something, which police said may be a device. Police came to us and said, 'You have to leave the shop because he has a bomb in his bag.'"
Images shared on social media showed a man lying on the sidewalk outside a pharmacy.
Stephen Roberts, a former deputy commissioner for the Metropolitan Police, said if the stabbings were carried out by a "self-starter" — someone acting alone — it means any city in the country is vulnerable to a similar sort of low-tech attack.
In November, British authorities lowered the national terror threat level to "substantial,'' meaning an attack is considered likely. That is the third-highest rung in a five-step system used by British authorities and marked the first time since August 2014 that the threat level had been so low.
It was lowered because of the belief that the threat of British jihadis returning to the country from Syria had been reduced by events there, including the Islamic State group's loss of territory.
It is not clear if the two attacks since then will lead the independent analysts who make recommendation to the government to suggest raising the level
London Mayor Sadiq Khan urged community resolve in the face of another attack.
"Terrorists seek to divide us and to destroy our way of life,'' he said. "Here in London we will never let them succeed."
Also Sunday, police in Belgium shot a woman who stabbed and wounded passersby in the city of Ghent, but prosecutors said there was no suspicion of terrorism or a link to what happened in London.
Jill Lawless contributed.