LONDON mayor Sadiq Khan was on the hit list of a teenager who gunned down 10 people at a supermarket in Buffalo in the US state of New York on Saturday (14), according to media reports.

A 180-page “manifesto” of Payton Gendron, who surrendered after the racist rampage, named Khan as a prominent “enemy” to be killed.

Khan, elected twice as the mayor of London, is the son of Pakistani immigrants and is a prominent figure in the British South Asian community.

Gendron, 18, believed to be “inspired” by a shooter who killed 51 people at two New Zealand mosques in March 2019, also referred to the organised child sex abuse in the English town of Rotherham, The Telegraph said.

The gunman shot four people in the Buffalo store’s parking lot, three of them fatally, before entering the supermarket. Among those killed inside was a retired police officer working as a security guard.

A spokesperson for Twitch said the shooter used the platform to broadcast the attack live and that the streaming service had removed the video within “two minutes.”

The rampage is being investigated as a federal hate crime “perpetrated by a racially motivated violent extremist,” Stephen Belongia, special agent in charge of the FBI’s Buffalo field office, said.

Mayor of London Sadiq Khan. (Photo by Leon Neal/Getty Images)

The police commissioner for the city in western New York, Joseph Gramaglia, told reporters the suspect did “reconnaissance” on the predominantly black area surrounding Tops Friendly Market and drove there from his hometown of Conklin, more than 200 miles (322 kilometres) away.

Wearing heavy body armour and wielding an AR-15 assault rifle, the shooter killed 10 people and wounded three others – almost all of them black – before threatening to turn the gun on himself. Police said officers talked the gunman down before arresting him.

The suspect was arraigned late on Saturday on a single count of first-degree murder and held without bail, the Erie County district attorney’s office said. He pleaded not guilty.

“The evidence that we have uncovered so far makes no mistake that this is an absolute racist hate crime,” Gramaglia said, adding Gendron had a rifle and shotgun in his car.

Buffalo Mayor Byron Brown was unequivocal about the shooter’s motivations: “This individual came here with the express purpose of taking as many black lives as he possibly could.”

Gramaglia said the gunman had last year made “generalised threats” at his high school, after which state police referred him to a hospital for a mental health evaluation that lasted approximately one day and a half. He was then released.

In Washington, President Joe Biden – whom the White House said would visit Buffalo on Tuesday (17) – condemned the racist extremism and “hate that remains a stain on the soul of America.”

The attack evoked memories of recent US history’s most devastating attacks, including a white man’s 2015 massacre of nine worshippers in a predominantly black South Carolina church, and the 2019 attack by a white man in Texas that claimed 23 lives, most of them Latino.