Five women say they were raped at Sweden's biggest music festival - on the same weekend as a mob of 'foreign youths' sexually assaulted 35 females, one as young as 12 at another concert.

Alleged victims at the Bråvalla music festival told police groups of men attacked them while others complained that they were filmed while using the toilets.

Two teenage girls said a man carried out a sex act in front of them.

Popular: Five women say they were attacked at the Bråvalla festival, the largest in Sweden, attracting some 52,000 revellers

Crowded: Police have come under fire for failing to protect festival-goers, as campaigners insist that the wristbands are not strong enough to prevent attacks

As well as reports of rape at the festival - headlined by Mumford and Sons - there was one report of attempted rape and 15 cases of sexual assault.

Two of the victims, most of whom were girls under the age of 18, said a man masturbated in front of them, while others said they had been filmed while using the toilets.

Police in Sweden have faced criticism for failing to do enough to protect the 52,000 festival goers.

Police spokesman Thomas Agnevik, who was also at the festival near to Norrköping, said he 'understands the criticism'.

'If a crime is being committed obviously not enough has been done,' he said. 'Nobody should have to go to a concert and leave as a rape victim.'

But he added said that police are almost powerless to protect festival-goers, as most of the attacks happen among crowds of people and often after dark, making it is 'very difficult' for them to spot those responsible.

'Two of the rapes happened in front of the stage in the crowd, another was in a tent and another in the public bathroom,' he added.

Complaints: Police spokesman Thomas Agnevik, who was also at the festival near to Norrköping, said he could 'understand the criticism'. Pictured, file image of the festival from 2015

Campaign: Police have handed out wristbands with 'Don't molest' written on them, in an attempt to crackdown on sexual assaults at festivals. Pictured, National Police Chief Dan Eliasson wearing one of the bracelets (left)

But he added: 'A handful of men have been taken in to be questioned as suspects. The victims are mostly young women under the age of 18.

'I won't comment about their background but they are young boys aged between 15 and 25.'

Two of the rapes happened in front of the stage in the crowd, another was in a tent and another in the public bathroom. Police spokesman Thomas Agnevik

Mumford and Sons said they would not play at the festival again until they receive assurances from police and organisers that they are doing something to combat 'disgustingly high' rates of reported sexual violence.

They said in a statement: 'We're appalled to hear what happened at the Bråvalla Festival last weekend. Festivals are a celebration of music and people, a place to let go and feel safe doing so. We're gutted by these hideous reports.'

It comes after 35 girls aged between 12 and 17 reported being attacked at the 'Party in the Park' festival this weekend in Karlstad, Varmland County.

Some of the alleged victims reported being 'kissed and groped' in scenes similar to the Cologne New Year attacks, in which dozens of women reported being assaulted.

One victim Alexandra Larsson, 17, waived her right to anonymity to tell MailOnline she was molested on Friday night having been looking forward to attending the festival for months.

'I do not know what to think, it is so wrong. Everyone thinks it's wrong but nothing happens,' she said.

'There are large festivals with several thousand people and these mass incidents create a powerlessness for both the police, security guards and especially for visitors who become victims.

'The perpetrators will be so anonymous in the audience that they will get away with sex crimes. That is the main problem, that the perpetrators get away with it.

Trauma: One victim Alexandra Larsson (pictured) told MailOnline she was molested on Friday night having been looking forward to attending the festival for months

Challenge: Police said that many festival sex attacks happen in areas where police have limited access, such as the crowd in front of the stage and the camping areas

'It's not okay. I should be able to go to festivals and have fun like everyone else without being afraid. It is wrong, really wrong, but that's the feeling I have after yesterday. It's damn hard that ordinary people who just want to have fun should have to suffer just because someone thinks it's fun to violate.'

Swedish police launched its new campaign a week ago, in an effort to crackdown on sexual assaults at festivals.