Why are people so excited about Swatch's Royal Pop watch?

The launch of an exclusive pocket watch has sparked a frenzy that forced stores worldwide to close and in some cases saw police officers and security deal with huge unruly crowds.

The Royal Pop watch collection, a highly anticipated collaboration between Swatch and luxury brand Audemars Piguet (AP), went on sale on Saturday in selected stores around the world.

Similar to past sales of its kind, some people queued for days to get their hands on one of the eight models.

But the ferocity of interest in the product, both online and on the high street, has split opinions about responsible marketing and whether the watches are even worth it.

Better known for its colourful watches from the 1980s, AP Swatch has described the Royal Pop collection as "a disruptive collaboration between two icons of Swiss watchmaking".

While original sales of the collection were exclusively in selected stores - with people only able to buy one £335 (€385; $448) watch per person - they have been driven by an online campaign that has lasted months.

Retail expert Catherine Shuttleworth said Swatch had done a fantastic job in teasing the product, drawing on younger shoppers' love of collaborations, exclusivity and newness.

"The hype has worked," she told the BBC, adding that the watch was aspirational, with shoppers able to pay a fraction of the usual cost for an AP product.

Watch reviewer and podcaster, Britt Pearce, agreed, describing these types of collaboration as "a flash in the pan, but they're a very exciting flash in the pan".

Swatch closed its stores in several cities across the UK after hundreds of people queued outside and the police were called in. There were reports of threatening behaviour and at least one arrest.

There have also been reports of scuffles in Amsterdam and Milan as well as in cities in Asia and the Middle East.

According to the Reuters news agency, police officers fired tear gas to control a 300-strong outside a Swatch shop near Paris, and four people reported being punched in the crowd outside a store in Lille, northern France.

Some watch enthusiasts in New York camped for a week and there were reports that people had become unwell during the wait.

In a social media post after crowds gathered at branches worldwide, Swatch asked people "not to rush to our stores in large numbers" and closed its stores for safety reasons once the crowds became too big.

The company has been criticised by some people, who say the watches should be available on its website and police resources had been unnecessarily diverted.

Pearce said Swatch seemed "to be creating dangerous situations for people to collect a watch".

"I think they know exactly what they're doing," she added.

However, Shuttleworth suggested Swatch could not have foreseen violence breaking out.

Shuttleworth also said online sales have also caused problems, with people using bots and other technology to try and cheat the system.

Swatch on Monday issued a statement, saying the response to the Royal Pop watch collection had been "phenomenal worldwide", adding that there had only been issues in 20 out of the 220 Swatch stores where the watches went on sale.

It compared the sale to that of the MoonSwatch - a 2022 collaboration with luxury watch maker Omega - when police called in and shops were closed.

"As with the MoonSwatch, the situation has now normalized somewhat after the launch day, especially after we communicated once again that the Royal Pop Collection will be available for several months," Swatch added.

Britt said she had visited one of Swatch's London stores on Friday night and saw security "starting to lose control a little bit" as the crowds increased in size ahead of the watch's release.

She said she also saw people leave the shop after buying a watch being met by people offering to give them double what they had paid for it.

While some people lining up to buy the watches are enthusiasts, others have been buying them up to sell them on for more online.

Jaylen told the BBC he got one of the watches on Sunday and had sold it for just over £1,000 - a profit of several hundred pounds.

"I'm coming back to buy more. It's one per person but I've got friends I've paid to get them from other shops," he said.

While there have been reports of Royal Pop watches being resold for huge sums online, the UK watch business magazine WatchPro cautioned that some of these were fake.

The BBC has also seen some Royal Pop watches listed on eBay for between £3,000-£5,000.

Ahmed, who has also bought one of the watches, told the BBC he was thinking longer term and would hold onto his for now, with it likely to significantly rise in value once the limited sale ends.

"Already they're going for over a grand on the market, so when they stop producing them all together and there's no more being introduced...it's a no brainer," he said.

There have been mixed reviews about the watch itself by people the BBC has spoken to.

"I feel it is something that can be treasured that you could pass on. It could be memorable, treasurable and go up in time if it is a limited stock," said Corzo, who has been queuing for days and said he has seen an improvement in the communication and cooperation of the crowds.

"Swatch collaborated with a really good brand - that's AP. And it's really good to have this in my watch collection," said another man, who queued for two days and slept in a tent.

Others were not so keen.

"I don't think it's worth the money or the time to queue up," said Tabassum, 18, who spoke to BBC Newsbeat in Birmingham.

"What's the fuss about," her friend, Meredith, said.

Britt Pearce said she had been excited about the collaboration of two well-known watchmakers and thought it might encourage people to take more of an interest in watches.

However, her experience at the London store had dampened this.

"I would say going there and being a part of it did sour my feelings," she said.

With additional reporting by Tim Muffett and Vinnie O'Dowd