Hundreds of fans flocked to Watford’s Asda today to see YouTubers' KSI and Logan Paul – causing travel chaos in the area.

The pair were in the town to exclusively launch their new Prime energy drink, with youngsters turning out in huge numbers.

They arrived on a red open top bus at around 4.30pm - around an hour later than planned - prompting the crowd to go crazy.

The Internet stars addressed crowds with a microphone before throwing down free cans of their drink before leaving after around ten minutes.

KSI, who was born and grew up in Watford, had announced the day before that he would be at the supermarket with American Paul to launch the drink they have created together.

Watford Observer: Fans near Watford's Asda. Picture: Ian Downey @Tridiver.Fans near Watford's Asda. Picture: Ian Downey @Tridiver.

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The Asda car park was filled with excited teenagers from around 2.30pm with crowds close to 1,000 or more estimated at one time.

With the supermarket still open and children running between cars, police arrived at around 3.30pm to help control the crowds and traffic.

After a boy on a bike was hit by a car by the entrance to the car park on the A41, officers made the decision to close all access into the car park and also stopped traffic on the A41.

The boy was attended to by a police officer and appeared to have suffered pain to his leg.

Around 20 police officers and ten police vehicles were spotted in the area attempting to control the situation.

And with all the chaos outside, some shoppers in Asda reported being kept inside by staff until things had calmed down.

A Hertfordshire police spokesperson said earlier: "Police were called at around 3.30pm today (Friday 17 June) to reports that a large crowd had gathered in the Colne Way area of Watford, causing disruption to the surrounding road network.

"Officers are currently on scene and road closures have had to be put in place as a safety measure.

"One person is reported to have been struck by a vehicle and is receiving treatment from the ambulance service."

Facebook Live of when KSI and Logan Paul arrived:

Watford Observer: Crowds near Asda. Picture: Ian Downey @TridiverCrowds near Asda. Picture: Ian Downey @Tridiver

Officers kept roads closed as crowds continued to wait for the stars, who have tens of millions of followers between them on social media, to arrive.

Their patience was rewarded when a red bus appeared at around 4.30pm prompting screeching and cheers. They stayed for around ten minutes, protected by a line of police officers, before being escorted out by police.

After his visit, KSI shared a tweet from Paul on baord at the bus at Asda, accompanied with a heart and 'Watford'.

It is thought to have been one of KSI's first public visits back to his hometown for some years.

Watford Observer: Picture: Ian Downey @TridiverPicture: Ian Downey @Tridiver

It took some time for crowds to disperse and traffic to clear out of the car park but the scene had calmed down and police had left by 5.15pm.

There were no signs of any trouble bar the incident involving the boy on the bike.

It is estimated nearly a thousand people were present, the vast majority of which were teenagers and children.

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