POLICE have issued another warning on the day a party – which attracted some 21,000 guests on Facebook and made headlines around the world – was scheduled to take place.

The Herts Advertiser revealed last month that a teenager had inadvertently advertised her birthday party publicly on the social networking site and within a matter of hours tens of thousands of people around the world had clicked the RSVP button.

The event was swiftly taken down but a number of spin off groups popped up re-posting the details of the Sir John Lawes student’s party including her address and phone number.

A number of fake celebrities – including Susan Boyle, Justin Bieber, Rick Astley and David Cameron – even joined the events and groups which also went on to attract thousands of members, but most of them have now been removed.

Despite the party being cancelled, there are still concerns that thousands of people may descend on the town tonight (Thursday).

Neighbourhood sergeant Lewis Ducket said plans are in place to minimise any possible impact on the local community such as officers being present to deal with any issues as well as support from the British Transport Police at the train station.

He continued: “Should large groups of people attend, officers will use every power available to maintain the peace for the benefit of the local community. Anyone who does come to Harpenden expecting to attend the location will be dealt with robustly by police and we will seek to ensure any persons under 16 are reunited with a parent or guardian.”

Sgt Ducket added: “In recent weeks we have been working with locals schools to pass out messages asking people not to attend and should any specific incident occur we will continue our work with schools in relation to this matter.”