Image copyright Gavin Baos Image caption Wales fan Gavin Baos admits he is "concerned" at causing offence in Japan

Welsh rugby fans travelling to Japan for the World Cup have been urged to cover up tattoos to avoid offending some of their hosts.

Hundreds of supporters are heading to the country ahead of Wales' opening game of the tournament on Monday.

Tattoos have long been associated by some in Japan with yakuza crime syndicates, and tattooed tourists could be barred from communal hot springs.

Fans are also being asked to wear shirts when using gyms or pools.

Gavin Baos, 42, from Cardiff, is spending 11 days following Wales in Japan with a group of friends.

Image copyright Gavin Baos Image caption Mr Baos has Maori and Celtic-themed body art

Mr Baos, a financial adviser, has extensive tattoos from elbow to wrist on both arms and covering much of his lower legs.

"They are pretty big tattoos so it has been a real concern," he said.

"A friend in Tokyo said there's no way you can go into some gyms or baths with tattoos as it would really cause offence.

"It's really important to know these customs because the last thing I want to do is cause offence.

"Normally I live in shorts, T-shirts and flip-flops but I've found myself buying long-sleeve shirts and jogging bottoms to have as a back-up, just in case.

"The only frustrating thing is that if it's 25 degrees and 100% humidity, it could get a bit uncomfortable."

Image copyright Getty Images Image caption Ross Moriarty is one of the Wales internationals with extensive body art

Keith Dunn, the honorary Japanese consul to Wales, said: "We like tattoos in Wales.

"I think making sure you understand the customs are different and making sure you cover up tattoos - if you're going to go swimming or to the gym, just cover up."

World Rugby, the sport's governing body, has posted advice to the estimated 400,000 travelling fans.

A 2015 survey found that 56% of hotels and inns did not allow tattooed guests to use communal bathing facilities.

Japan's tourism agency has called on spas in the country to relax their rules.

The organisation suggested that hot springs - onsens - and bath houses could offer visitors stickers to cover up tattoos, or set aside specific times of day when tattooed bathers can use the facilities.

Media playback is unsupported on your device Media caption The end of Japanese tattoo art?

Strachan Sports Travel, of Cowbridge in the Vale of Glamorgan, is taking six tour groups of Wales fans to the tournament, which runs between 20 September and 2 November.

General manager Angharad Griffiths said: "It may be a little more relaxed during the World Cup, so not to upset certain cultures.

"However we have advised anyone with tattoos that there may be occasions when they need to cover them."

The advice is not limited to fans, with tattoos common among players, especially Pacific Islanders and Maoris.

Image copyright Getty Images Image caption Wales player James Davies had his nickname "Cubby Boi" tattooed during a trip to Las Vegas

While not required during matches, visiting players and officials have been warned by World Rugby to cover up in public.

A Welsh Rugby Union spokesman said: "Having toured Japan in 2013 and visited the country on many occasions as part of our Rugby World Cup preparations, the management and the squad are looking forward to embracing the local culture and will of course comply with all protocols."

New Zealand and Samoa players in Japan are already covering up in hot springs, hotel lobbies and other public areas.

"We've got an onsen, or a spa, at every hotel," All Blacks scrum-half Aaron Smith told the New Zealand Herald.

He said in a public spa the players had to wear clothes to cover tattoos.

"And that's okay, we're in Japan, we have to embrace their way, their culture," he said.

Travelling fans have also been advised to check what medication can be taken into Japan amid restrictions.