WINDSOR, United Kingdom: On the eve of Prince Harry and Meghan Markle’s wedding, the picturesque town of Windsor has taken on the character of an impregnable fortress. Every nook and cranny has been scoured and every imaginable security measure deployed to guarantee the safety of the royal couple and the tens of thousands of spectators set to flood the streets. In a dress rehearsal Thursday for the journey Harry and Meghan will take through the town after the Windsor Castle ceremony, uniformed police — some armed — were out in force. On one of the roads near Windsor Castle — where Queen Elizabeth II often spends weekends — officers used handheld torches to examine street lights, traffic lights, rubbish bins and manholes, anywhere along the road where a suspicious device could have been hidden. “We’re just checking to make the wedding safe,” one said as his colleague led a sniffer dog on a hunt for hidden explosives. Huge barriers have been hauled into place to prevent a vehicle attack and many roads are now closed in the town of 30,000 inhabitants, 30 kilometers (19 miles) west of London. Number plates are also being automatically scanned and surveillance cameras have been deployed en masse. Two months in the planning, the security measures are in line with the huge crowds expected. The wedding is expected to attract around 100,000 spectators in Windsor itself, with at least 5,000 journalists, according to Thames Valley Police. “A broad range of visible security measures are in place,” a spokesman said. On D-day, train stations will be on high alert, vehicles will be inspected and visitors can expect to be searched. No drones will be allowed to fly over the wedding zone. “Things can go wrong whenever you have big crowds of people,” Chris Phillips, former head of Britain’s counter-terrorism security office, said. “Terrorism is obviously the biggest threat.” “You have to treat everyone as a possible troublemaker or terrorist,” said Phillips, who now runs security consultancy IPPSO. Sent reeling after a series of attacks by the Daesh group in 2017, Britain’s current terror threat level is “severe” — the second highest it can possibly be — indicating an attack is “highly likely.” But if “everyone can be a threat” then “everyone also can be a positive pair of eyes,” said ex-police officer Phillips. More than a terror attack, one local seems to fear the hordes of well-wishers set to descend on the town. Rekha Parker will try to take her daughter to see the newlyweds on Saturday, but will call off the effort if the crowds are too dense. “If it’s too busy then I’ll go back home,” she said. “There’s more than enough police but at the end of the day if people are going to strike, they are going to strike,” said her friend Leigh Smith, a 40-year-old mother. For the royal couple themselves one of the greatest risks is their open-top carriage procession “You can make sure there’s no room for snipers and things and just don’t let people to get too close to it. It’s the key,” said Phillips. Totally eliminating the risks on the day is an impossible task, but police have assured residents “there is no intelligence to suggest that the event is a target.” Local councils have also deployed dozens of “ambassadors,” volunteers who will guide visitors but also act as extra sets of eyes and ears on the ground. “We report anything that looks suspicious. We’ve just recovered a rucksack this morning, fortunately we could find the owner,” ambassador Bob Gardner said. The number of police set to guard the ceremony has not been disclosed, but is “probably at least thousands,” according to Phillips. That is to say nothing of the cost of the security, which will be billed to the British taxpayer.