A person is in custody after right-wing American influencer Charlie Kirk, a staunch ally of Donald Trump, was shot dead at a university event in Utah.

The US president announced the death of the 31-year-old conservative, hailing him as a"great, and even legendary" figure who was "loved and admired by all, especially me".

"No one understood or had the heart of the youth in the United States of America better than Charlie," he added.

In a post on X several hours after the shooting at Utah Valley University, FBI director Kash Patel said an individual had been taken into custody.

Speaking at a news conference on Wednesday afternoon, Utah Governor Spencer Cox described them as a"person of interest". He labelled the killing as a"political assassination".

Authorities said the shooter wore dark clothing and fired from a roof on the campus.

A suspect taken into custody earlier was released as they did not match the description.

Earlier, witnesses said they heard shots fired from a nearby building as Mr Kirk spoke, a university spokesperson told Sky's US partner NBC News.

Videos on social media show Mr Kirk talking into a microphone while sitting under a white tent with the slogans"The American Comeback" and "Prove Me Wrong".

A single shot is heard, and Mr Kirk can be seen reaching up with his right hand as blood comes out from the left side of his neck. He then falls off his chair.

A university spokesperson confirmed he had been shot in the neck. He was then taken to hospital by private security and underwent surgery.

Mr Trump earlier asked people to pray for the activist.

Who was Charlie Kirk?

The father-of-two was the chief executive and co-founder of Turning Point USA, a prominent organisation that engages conservative youth on school campuses.

The university had said a suspect was in custody but later clarified that was not the case.

Mr Kirk and Turning Point USA played a key role in driving youth support for Mr Trump in last November's presidential election. His events at college campuses nationwide typically draw large crowds.

Mr Trump often spoken favourably about Mr Kirk, including multiple times on the campaign trail last year.

During a rally in Washington the day before he was sworn in for a second term in January, Mr Trump told attendees:"Charlie Kirk is here. And I want to thank Charlie. Charlie is fantastic. I mean, this guy."

A few weeks before, during a rally in Las Vegas on 22 December 2024, Mr Trump called Mr Kirk"incredible", adding that he"is a special talent, and he's out there fighting".

He also appeared last October at a Turning Point USA political rally in Phoenix, saying:"I want to express my tremendous gratitude to Charlie Kirk. He's really an amazing guy. Amazing guy."

Tributes from across the political divide

Tributes have come in from across the political divide in America since news of his death emerged, notably from the former president Barack Obama.

"This kind of despicable violence has no place in our democracy," he said."Michelle and I will be praying for Charlie's family tonight, especially his wife Erika and their two young children."

Politicians overseas were also quick to react, with Reform UK leader Nigel Farage - a regular at US conservative campaign events - saying it was"a very dark day for American democracy".

Tory leader Kemi Badenoch said it was"a blow to everything Western civilisation stands for: open discourse, robust debate and peaceful dissent".

Prime Minister Sir Keir Starmer described his death as"heartbreaking", adding:"We must all be free to debate openly and freely without fear - there can be no justification for political violence."

And Israel's Benjamin Netanyahu hailed him as a "lion-hearted friend of Israel" dedicated to "speaking truth and defending freedom".