The Pokemon Go app could lead to an increase in illegal mobile phone use by drivers, motoring experts warned.

The RAC said the growth of the app means there is "yet another reason" for motorists to concentrate on their smartphones instead of the road in front of them.

Pokemon Go was released in the UK on Thursday after overtaking Tinder in the US in popularity.

RAC road safety spokesman Pete Williams said: "The Pokemon Go revolution could take the illegal use of hand-held mobile phones at the wheel to another level.

"It has to be Pokemon no-go when driving but it is just as important that pedestrians don't get caught in the Pokemon mist and find themselves stepping into the path of danger.

"This feels like a whole new level of gaming addiction and yet another reason for people to be glued to their smartphones instead of looking where they are going."

Samson Ruwangu, digital content executive at road safety charity IAM RoadSmart, claimed "driving a car is the last place you should be looking for Pidgey, Rattata or the others".

He went on: "I nearly tripped over playing this game. Pokemon Go makes you concentrate on catching characters and it takes both hand and eye coordination."

AA president Edmund King posted on Twitter: "This Pokemon Go craze is taking over world highways. We had smartphone zombies, don't want Pokemon addict zombies."

An RAC study published earlier this year found that almost two-thirds (64%) of motorists witnessed at least one driver using their phone illegally during their last hour on the road.

Some 6% of the 2,120 people polled reported seeing between five and seven drivers breaking the law in this way.

In 2014 the use of a mobile phone was a contributing factor in 21 fatal accidents and 84 which were classed as serious, according to Department for Transport (DfT) statistics for Britain.

The Government is currently examining responses to a consultation held earlier this year which proposed introducing tougher punishments for drivers caught using their phone behind the wheel.

Ministers are considering raising penalty points for those caught from three to four, while fines could rise 50% to £150.

Drivers can be banned from the road if they receive 12 points within three years.