POLICE in Windsor have embarked on one of the most significant search operations in their history, as they scour the streets ahead of Prince Harry and Meghan Markle's wedding in a bid to keep more than 100,000 visitors safe.

Specialist explosive detection dogs from Thames Valley Police searched through the town examining letter boxes and phone booths for signs of potential explosive devices.

With a month to go until the big day residents will notice more CCTV cameras, extra technology to recognise number plates and “hostile vehicle mitigation barriers” to protect pedestrians from terror attack by cars or heavy duty vehicles.

Police search coordinator Andy Turner, who handles seven-year-old black Labrador Toby, said: “Having been on the police force for 27 years it's really something to be retiring from service on the weekend of the wedding.

“This is a large operation for any police force and one of the biggest I have worked on. We of course want it to all go smoothly and the focus be on the two people in love getting married.”

In 27 degree heat on what has been the hottest day of the year so far Windsor town was heaving with locals and tourists coming to catch a glimpse of the Castle.

Scott Bowyer, 24, who had travelled from Ascot for the day said: “Hopefully everybody wants to just come together for the celebration and enjoy the wedding but seeing the police out like this is definitely reassuring.

“I think because of past events it is in the back of your mind that something could happen but seeing the dogs searching at this stage and so thoroughly it comforting.”

Nearly all officers from the force will be working on the day with all leave requests being denied for the weekend.

Police teams checked through drains for potentially dangerous devices and carried out searches in Home Park in the shadow of Windsor Castle.

PC Aaron Sinclair-Day who has worked on the force for five years said: “Searching drains may seem strange but you can never be to careful.

“The task of policing the wedding is of course a lot of work and the biggest operation I have taken part it.”

The operation, believed to be the largest in the force’s history, will also see a step up in police dog patrols that are already regularly seen in Windsor.

Sergeant Turner added: “This is business as usual for us. Windsor Castle is an iconic location and therefore we often have patrols in the area.

“There is a large uniform presence but we ask that if people do see something that doesn't look right to let us know.”

Police dog searches were also being carried out in Windsor this week as Commonwealth heads of government are expected to visit on Friday.

For the wedding Windsor will be cordoned off and people will have to go through full body scanners to get to the town as part of the royal wedding security measures.

A "screening and search" regime will be introduced in the run-up to the event at St George's Chapel on 19 May.

Police have not announced he exact date of when the secure zone would be implemented for security reasons.

Shops and buildings will be searched in the days leading up to the wedding and plans are in place to stop trains from calling at Windsor station if the numbers of people in the town causes a "public safety risk".

Police officers, both armed and unarmed, search dogs, police horses and the National Police Air Service will increase their presence in the coming weeks.