DON'T mess with the royal wedding.

That's the message British authorities are sending out about security arrangements as Prince Harry and Meghan Markle plan to tie the knot on Saturday.

Snipers in full military gear roamed London's streets - with officers given orders to "do whatever is necessary," and also to shoot to kill, according to the New York Post.

 

Armed police patrol Windsor as preparations ahead of the wedding of Prince Harry and Meghan Markle tomorrow. Picture: AP Photo/Frank Augstein
Armed police patrol Windsor as preparations ahead of the wedding of Prince Harry and Meghan Markle tomorrow. Picture: AP Photo/Frank Augstein

"Operations will have been planned for months," security expert Will Geddes told the Daily Star.

"Police will have mapped the area, established risk profiles and worked out the modus operandi of high-risk groups."

He added: "Police will be looking for a variety of threats," including ISIS terror threats, stalkers, and YouTube pranksters.

The $53 million ($40 million US) security bill for a "ring of steel" perimeter is even higher that that of Prince William and Kate Middleton's wedding day, according to The Sun.

A police sniffer dog checks the crowd as Prince William and Prince Harry greet the crowd waiting outside the castle in Windsor, England.
A police sniffer dog checks the crowd as Prince William and Prince Harry greet the crowd waiting outside the castle in Windsor, England. AAP

The country has been on high alert after a spate of terror attacks, including incidents on London Bridge, Westminster Bridge and Manchester Arena.

Vehicular attacks, as well as those by a lone attacker with a knife, could spark pandemonium in the crowds. The objective of such attacks would be publicity, Mr Geddes said

"The world will be watching - nothing can afford to go wrong," he said.

Police also have asked the public not to toss confetti or other festive items during the event - citing security - and sanitation concerns, according to the Windsor & Eton Express.

"Please do not throw confetti or any other items at any time during the day, particularly during the procession.

It poses a potential security risk and it's a bit of a pain to clean up!" the Thames Valley Police tweeted.

Prince Harry meet members of the public outside Windsor Castle ahead of his wedding to Meghan Markle this weekend.
Prince Harry meet members of the public outside Windsor Castle ahead of his wedding to Meghan Markle this weekend. AAP

This article first appeared in the New York Post and is republished with permission.



The plan to save our crops as backpacker numbers drop

Premium Content The plan to save our crops as backpacker numbers drop

PRIOR to Covid-19, there were 160,000 seasonal workers in Australia

FULL LIST: 82 people to appear in court today

Premium Content FULL LIST: 82 people to appear in court today

List of those appearing in court today

GRAPHIC IMAGES: Woman fined for emaciated dogs

Premium Content GRAPHIC IMAGES: Woman fined for emaciated dogs

MAGISTRATE: “YOU had the best of intentions … but animals are easy to love, but are...