UPDATE: 

6:10PM (PST)

The security minister, Ben Wallace, has called for vigilance. He calls the incident an attack; police have said they are treating it as possible terrorism, but we are waiting for confirmation.

Wallace said:

“In the light of the attack in Manchester tonight, please be vigilant and if you see anything suspicious call the anti-terrorist hotline: 0800 789123.

My thoughts are with all the victims of the incident tonight and our emergency services who are out there tending wounded and keeping us safe.”

5:55PM (PST)The concert reportedly started and finished late, about 45-minutes behind schedule. Had the concert finished earlier it is believed there would have been a much greater number of people close to the site of the explosion.

5:50PM (PST) 

We are told that Grande will cancel her London performance at the O2 Arena on Thursday, due to safety concerns, and because she is “in no condition to perform,” after learning that dozens of her fans have been gravely injured or killed in Manchester this evening.

5:48PM (PST)

Elena Semino, from Lancaster, was with her husband waiting for her daughter by the arena’s ticket office when the explosion went off. She has a wound on her neck and her leg is bleeding. She hasn’t been seen by a doctor yet as her priority was finding her daughter – which she now has.

“My husband and I were standing against the wall, luckily, and all of a sudden there was this thing. I can’t even describe it. There was this heat on my neck and when I looked up there were bodies everywhere.”

Her husband stayed behind to help an injured woman and has a minor injury. She ran to find her daughter in the auditorium.

Semino’s 17-year-old daughter Natalie and her friends said the performance had just come to an end when the explosion went off. “It went off and then there was a moment’s silence and then there were screams,” says Megan Ryder, 19. They say security guards initially tried to calm them down, saying it was a popped balloon or a technical difficulty.

5:45PM (PST)

Facebook has activated its safety check for people who are at or near the arena to let family and friends know they are safe.

5:40PM (PST) 

The second suspected explosive device was determined to be a pile of “abandoned clothing,” but was detonated out of “extreme caution.”

5:35PM (PST) 

Witnesses, and injured concert goers tell PopWrapped that there were “loads of nails and metal nuts on the floor.” Another witness to the carnage describes being covered in “blood, skin and burnt hair.”

5:22PM (PST)

A second suspected explosive device has been found near where the first explosion occurred, Manchester police tell PopWrapped. The device will be detonated in a controlled explosion, momentarily, police assure us.

5:20PM (PST)

Manchester Police tell PopWrapped ” A bomb was detonated just outside the arena, as people were leaving. The bomb was placed in an area and at a time intended to inflict the most carnage, death and destruction. We are also aware of gunshots fired outside the arena. We do believe this was a suicide bombing, and are searching for additional suspects.”

5:13PM (PST)

Manchester Police are calling this incident “a definite act of terrorism.”

5:10PM (PST)

ISIS has claimed responsibility for the attack, in a series of tweets from user @OWYS663, which has since been suspended by Twitter. The tweets were sent out before the explosions, and claimed that there would be more attacks than the Manchester Arena attack. 

BREAKING:

Authorities in Manchester are calling it “the most despicable kind of terrorism.” In Manchester, England, thousands of Ariana Grande fans filled the Manchester Arena. Grande had just finished her final encore, when several explosions rocked the entire arena and surrounding neighborhood. There was initial confusion about a possible electrical issue, baloons popping, or blown speaker, but the crowd soon realized they were in grave danger. Swarms of panicked concert goers poured out of the venue, resulting in additional injuries and deaths. British Police tell PopWrapped that the injuries are “consistent with pressure cooker nail bombs.”  Grande, in the middle of a world tour that spans Europe over the next month before shifting to South America, the 23-year-old pop star behind such hits as “Problem,” “Side to Side,” and “Break Free” was wrapping up another show when the explosion rattled the area just outside the concert hall.

Employees at local Manchester hospitals tell PopWrapped that “mass casualties are expected and prepared for.” Hospital staffers have been warned that their shifts could exceed 48-hours.  Police have already confirmed multiple fatalities. Reports are that at least 23 are dead, more than half of those, kids under 18, with more than 60 additional wounded. Local Police are warning everyone to avoid the area, and the Tube is also avoiding all stops in the area.  The Manchester Arena, opened in 1995, can hold up to 21,000 spectators; it was not clear how many people were in the crowd for the concert, although we are told the show was nearly sold-out. We have confirmed with Grande’s reps, who tell us the singer is “safe and unhurt,” noting that her biggest concern is the “safety of everyone involved.” BIA, Grande’s opening act, Puerto Rican-Italian rapper BIA, wrote in a now-deleted tweet: “Guys we are okay! Thank you we love you.” Parents separated from their children during the mayhem were urged to go to a Holiday Inn, where many children had taken refuge.  

Musicians and celebrities from around the world expressed their condolences to Grande and the concertgoers inside Manchester Arena.

“My prayers go out to ppl of Manchester… Had special times there from youth & beyond,” Cher tweeted.

“Praying for everyone at @ArianaGrande’s show,” Katy Perry wrote on Twitter.

“Tearing up imagining innocent concert goers losing their lives.. praying for everyone and all #arianators,” Demi Lovato tweeted.

PopWrapped will continue to update this story, as details become available.