A police officer stands guard near to the scene where a man was shot and killed by armed police on Feb 2, 2020 in London, England. (HOLLIE ADAMS / GETTY IMAGES / BLOOMBERG)

UK police officers shot and killed a man in south London who stabbed two people in a terrorism-related incident that the Metropolitan Police said was “Islamist-related.”

Police said a third person received minor injuries probably caused by glass following the discharge of a police weapon. All three victims were taken to London hospitals, one with life-threatening injuries. Specialist officers established that a device strapped to the suspect’s body was a hoax explosive.

Islamic State has claimed responsibility for the attack without giving evidence, the group’s Amaq news agency said on Monday.

Police officers were immediately on the scene in Streatham because of a “proactive Counter-Terrorism operation,” Lucy D’Orsi, the Met’s deputy assistant commissioner, said in a statement Sunday. 

Terrorists seek to divide us and to destroy our way of life

Sadiq Khan, Mayor of London

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Sudesh Amman, the man shot dead by police on Sunday, had been jailed for promoting violent Islamist material and had encouraged his girlfriend to behead her parents.

In November 2018 he pleaded guilty to possession of terrorist documents and disseminating terrorist publications, and the following month he was sentenced to more than three years in prison.

When officers examined his computers and phone, they found he had downloaded material about making explosives and carrying out terrorist attacks, according to police.

Messages showed that he had discussed with his family, friends and girlfriend his extreme views and desire to carry out an attack, often focused on using a knife, police said.

In December 2017 Amman posted a picture of Islamic State leader Abu Bakr al-Baghdadi, who was killed during a US raid in Syria in October, and told his brother in a message that “the Islamic State is here to stay.”

He also described Yazidi women as slaves and said the Koran made it permissible to rape them, and in another message he encouraged his girlfriend to behead her parents.

READ MORE: UK police: Bridge attacker had been jailed for terror crimes

According to the Guardian newspaper, the attacker was under active surveillance and the subject of a live investigation.

“Terrorists seek to divide us and to destroy our way of life,” Mayor of London Sadiq Khan said in a statement. “Here in London we will never let them succeed.”

The attack is the latest in a series of terror-related incidents in the British capital. Two people were killed near London Bridge in November, and eight people died in another attack at the same location in 2017.

British Prime Minister Boris Johnson said his government would set out tougher rules on releasing people convicted of terrorism offences.

“Those measures will build upon the actions we have already put in place,” said his interior minister, Priti Patel. She said there would be legislation to end the early release from prison of counter-terrorism offenders.

“It is right that these individuals are kept behind bars,” Patel said.