Police attending to the scene. Photo PA Guests arriving at the UMA 2008

It is reported by Police that a man in his 20s is in critical condition after being stabbed at the 6th annual Urban Music Awards ceremony held at the o2 Arena in London. Another person was left with minor wounds after a brawl errupted in a smaller part of the Arena.

Guests reported that chairs and champagne bottles were thrown, forcing organisers to call off the event just ninety minutes after it had started.

Top urban acts including Estelle, Adele, Leona Lewis, Dizzee Rascal and Duffy were among the nominees for awards.

Speaking to The Guardian, Andre Nevling, 24, said a woman sitting at his table ended up drenched in blood.

"Obviously the guy who got stabbed must have run straight past her and she's pretty shaken up," he said.

"I came out of the auditorium and looked at her and she was just standing there. I saw blood all over the floor and then I was like, 'Jesus you're covered in it'," he said.

There were complaints of security measures being 'light'. Natalie Williams, 32, said:

"There was no security, nothing. Before anything even happened I commented to my boyfriend, because we live nearby and come here a lot, and we usually get screened coming into the building. Tonight there was nothing."

Another guest, Emma Fairclough, said there were reports of guns being spotted at the event. She said: "I have spoken to two people who said they have seen guns in the arena this evening."

Speaking to the BBC Mike Muller, 38, from London, said there was a lot of confusion and hysteria.

"The company I work for, Intensify Youth, were presenting an award."

"Our man was just about to go on stage and present the award when this happened. "

"The irony is Intensify Youth is a project that aims to combat knife crime so this is really disappointing."

An O2 spokesperson said:

"Nothing of this nature has ever taken place in the venue before and all the usual stringent security measures were in place. "

"We are working closely with the police to understand how this happened. Our thoughts are with the victims of the attack."

The Urban Music Awards claims to be the "NO. 1 premiere Urban and Dance Music awards ceremony in the world" and was "born out of the need to build a worldwide and independent awards ceremony to recognise the achievement of urban based artists ... previously unrecognised within their country of origin ..."

Police reported that they were interviewing hundreds of people who attended the show. One man has been arrested.