Giant projections of Donald Trump alongside paedophile Jeffrey Epstein have been beamed on to Windsor Castle by protesters as the US president arrived in the UK for his second state visit.

Mr Trump has faced mounting questions about his relationship with the disgraced late billionaire after messages allegedly sent to him by the US president were published by Congress earlier this month.

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The apparent notes – which Mr Trump denies having written – appeared in a 2003 “birthday book” for Epstein.

Four people were arrested on “suspicion of malicious communications” after the images of Mr Trump and Epstein appeared on the landmark, Thames Valley Police said.

Two men were also arrested for breaching airspace restrictions in place for Mr Trump’s visit.

The president is being feted with a stay in Windsor Castle, where he will be hosted by the King and treated to a ceremonial welcome on Wednesday and later, a lavish state banquet.

The Prince and Princess of Wales will meet the president and first lady Melania Trump in the grounds of the Windsor estate, where he will spend the day, before heading to the prime minister’s country residence Chequers on Thursday.

It is hoped the Queen – who pulled out of attending the Duchess of Kent’s funeral on Tuesday after suffering from acute sinusitis – will recover in time to attend the busy run of royal events.

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There are no public-facing engagements for the president throughout his 48-hour state visit, with thousands of people expected to take part in a major protest against his stay in central London today.

The Metropolitan Police said it is preparing for “a significant operation” with as many as 50 protest groups expected to take part.

More than 1,600 officers will be deployed, including 500 assisting from other forces.

A small group of protesters from the Stop Trump Coalition were in Windsor on Tuesday night.

Two protesters from the activist group Fossil Free London were escorted out of a dinner organised by Republicans Overseas UK at Windsor Guildhall in the Berkshire town.

They chanted “how many will you kill if you drill baby drill” and unfurled a banner that said: “Oily Money Kills” at the event.

Speaking to reporters mid-flight, Mr Trump said: “My relationship is very good with the UK, and Charles, as you know, who’s now King, is my friend.

“It’s the first time this has ever happened where somebody was honoured twice. So, it’s a great honour.”

He told the journalists “everybody is looking forward to it. You’re going to have the best pictures”.

Tyler Robinson has been charged with the murder of right-wing US influencer Charlie Kirk.

The 22-year-old, from Washington, Utah, was charged with aggravated murder, weapon, and obstruction of justice offences ahead of a court appearance later on Tuesday.

Prosecutors said they would seek the death penalty and that Robinson’s DNA was found on the trigger of the alleged murder weapon.

A note was also found under his keyboard which said: “I had the opportunity to take out Charlie Kirk and I’m going to take it,” according to a charging document from prosecutors.

It is also alleged that the suspect ordered his roommate to delete “incriminating texts” about the killing and to stay silent if questioned by police.

When his roommate texted to ask if he was the “one who did it”, Robinson replied: “I am, I’m sorry,” prosecutors allege.

Robinson is said to have written in another text: “I had enough of his hatred. Some hate can’t be negotiated out.”

He also allegedly wrote he had been planning the shooting for just over a week.

Kirk, 31, was killed at one of his rallies at Utah Valley University last Wednesday.

The political activist, a close ally of US President Donald Trump, died after being shot in the neck with a bullet.

County attorney Jeff Gray said “aggravating factors” in the killing included that the “defendant is believed to have targeted Charlie Kirk based on his political expression and did so knowing children were present and would witness the homicide”.

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The obstruction of justice charges relate to allegations that Robinson disposed of the weapon used in the killing, along with clothing he is said to have worn at the time.

Robinson has been held without bail since his arrest.

Investigators have spoken to Robinson’s relatives and have carried out a search at his family home, 240 miles (385km) southwest of where the shooting took place.

Mr Gray said Robinson had accused Kirk of “spreading hate” during a conversation with his father. He also allegedly described the university as a “stupid venue” for the influencer to hold an event.

After the shooting, the county attorney said the suspect confessed to his parents after they confronted him, telling them he shot Kirk because “there is too much evil in the guy”.

Robinson’s mother told police that her son had become more political and had “started to lean more to the left” in the past year or so, Mr Gray said.

He added that the 22-year-old had become more “pro-gay and trans-rights oriented”, according to his parents.

His mother said he had started to date his roommate, who was “transitioning genders”, prompting “discussions” with his father who had very different political views.

Robinson allegedly wrote in another message to his roommate that “since Trump got into office [my father] has been pretty diehard Maga”.

The FBI director has shouted at Democratic senators during a hearing, taking questions on the assassination of Charlie Kirk, Jeffrey Epstein and the firing of agents.

Kash Patel was testifying before a Senate Judiciary Committee for the first oversight hearing of his tenure as director of the US federal law enforcement bureau.

During the hearing on Tuesday, Mr Patel defended the FBI’s handling of the investigation into the killing of Mr Kirk, as well as his social media post saying that a suspect had been arrested, before that person was ultimately released.

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“Could I have been more careful in my verbiage and included ‘a’ subject instead of ‘the’ subject? Sure,” he said of the post.

Democratic senator Cory Booker opened his questioning by accusing Patel of lying about firing FBI agents out of retribution for political investigations.

Five FBI agents and top-level executives were known to have been summarily fired last month, according to the Associated Press.

Mr Booker said that the director “pushed out senior FBI agents with decades of knowledge and experience”, and added: “You’ve shifted the agency’s priorities primarily to pursuing Donald Trump’s immigration enforcement agenda.

“I believe you have made our country weaker and less safe.”

Mr Patel responded that “you don’t get to say that America is not safer under this leadership”, and said that Mr Booker’s “rant of false information does not bring this country together”, prompting the Democrat to raise his voice.

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The two then shouted at each other before committee chair and Republican senator Chuck Grassley banged his gavel to interrupt them.

“I’ve watched him talk over us, and you’ve never once criticised him for us,” Mr Booker said to the chair as he got up to leave the room. “He has been really disrespectful to senator after senator.”

Mr Patel also clashed with Democratic Senator Adam Schiff, who questioned the FBI and Trump administration’s handling of questions relating to the deceased paedophile financier Epstein.

The director accused him of “the biggest fraud to ever sit in the United States Senate” as they shouted at each other, and said “you are a political buffoon, at best”.

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Mr Patel, a former lawyer who has been accused of spreading conspiracy theories, was controversially nominated to be the FBI director by US President Donald Trump last year.

He was narrowly confirmed by the Senate in a 51-49 vote in February. Two Republicans voted against his nomination.