A police van and an ambulance are seen outside the Manchester Arena, where U.S. singer Ariana Grande had been performing, in Manchester, northern England, Britain May 22, 2017. REUTERS/Jon Super

 

MANCHESTER: At least 19 people were killed and 50 injured in an explosion at Manchester Arena, where 23-year-old American singer Ariana Grande was performing in a concert.

In a statement issued early morning, the Greater Manchester Police said it is "being treated as a terrorist incident until police know otherwise".

?This story has been updated in real-time.

Update [6:30 AM PST]: Initial signs point to a suicide bomber as the cause of a blast, two US officials who spoke on condition of anonymity said.

Update [6:20 AM PST]: British politicians have started releasing their statements on the horrific Manchester Arena blast.

British Prime Minister Theresa May has said her thoughts are with the victims and families of those affected in "what is being treated by the police as an appalling terrorist attack", Express UK reported.

Labour Party leader Jeremy Corbyn said, "My thoughts are with all those affected and our brilliant emergency services."

Liberal Democrat leader Tim Farron also tweeted a message.

On the other hand, US House of Representatives Speaker Paul Ryan stated that he is "praying for the victims and their families".

Update [6:00 AM PST]: A Twitter user tweeted photos of those who have been reported missing and others who have been found.

Update [5:49 AM PST]: The GM police officers engaged in the "precautionary controlled explosion in Cathedral Garden confirm that it was abandoned clothing, not a suspicious item", GM Police said on Twitter.

Update [5:35 AM PST]: The GM Police, in an update, said they intend to carry out "a controlled explosion in Cathedral gardens shortly if you hearing anything don't be concerned".

Update [5:15 AM PST]: The GM Police has released fresh information pertaining to the Manchester Arena blast.

Update [5:12 AM PST]: Speculations surrounding the blast indicate that a 'nail bomb' was used, Geo News reported.

Update [5:10 AM PST]: American media is terming the incident as a "terrorist act", Geo News reported.

Update [5:00 AM PST]: The North West Counter Terrorism Unit is treating the incident in Manchester as a possible terrorist incident, sources said.

Senior national Counter-Terrorism officers are assembling in London and are liaising with the Home Office.

Investigative teams and British Police have cordoned off a one-mile-radius area. In addition, a taxi service is offering free rides to those affected to facilitate commuting from the scene.

Geo News reporters were refused to enter the area, while police refrained from making any comments to them.

Update [4:45 AM PST]: A bomb disposal squad has reached the site of the explosion.

The Oxford Circus venue nearby has also been evacuated.

Police officers are seen outside the Manchester Arena, where U.S. singer Ariana Grande had been performing, in Manchester, northern England, Britain, May 22, 2017. REUTERS/Jon Super

 

Update [4:30 AM PST]: According to unconfirmed reports from unofficial sources, as many as 25 people are dead, while over 100 have been injured.

Note that the police have only confirmed fatalities in the incident, but not provided a number yet.

Update [4:21 AM PST]: Helicopters have been summoned to the site for additional medical assistance. British police have termed it a "serious incident".

"We were making our way out and when we were right by the door there was a massive explosion and everybody was screaming," concert-goer Catherine Macfarlane told Reuters.

"It was a huge explosion ? you could feel it in your chest. It was chaotic. Everybody was running and screaming and just trying to get out."

Update [4:10 AM PST]: More than 50 ambulances are currently present at the site.

An ambulance drives away from the Manchester Arena, where U.S. singer Ariana Grande had been performing, in Manchester, northern England, Britain, May 23, 2017. REUTERS/Andrew Yates

 

Update [4:02 AM PST]: The GM Police says "there are a number of confirmed fatalities".

Update [3:35 AM PST]: A spokesman for Ariana Grande's record label said the singer was "okay".

Update [3:32 AM PST]: The area around Manchester Arena has been cordoned off, with security authorities asking people to "stay away" from the area. Ambulances and emergency teams rushing to the site.

Update [3:31 AM PST]: Some people on social media say the blast may be a balloon at the venue.

Update [3:30 AM PST]: Unconfirmed reports indicate a man has been apprehended while trying to escape during the stampede, Geo News reported.

Update [3:25 AM PST]: Services at the Victoria Park Railway Station have been suspended following the incident.

Initial report [3:20 AM PST]: Reports of a blast at Manchester Arena, UK, surfaced late Monday night, with Greater Manchester Police confirming "an incident".

American singer Ariana Grande was performing at Manchester Arena, a venue in the northern English city.

At least 19 killed in blast at Ariana Grande concert in British arena

If confirmed as an incident of terrorism, it would be the deadliest attack in Britain by militants since July 2005

Police have issued a warning to "stay away from the area", following two blasts that led to a stampede, with almost 15,000-20,000 attendees trying to escape.

Videos from the site surfaced social media.

Another video clip has emerged that, by chance, recorded the sound of the blast.

Most of the nearby arenas have also been evacuated. It is noteworthy that most of the locality has residential apartments and student hostels.

Celebrities also started issuing comments on social media.

"Manchester Arena, the largest indoor arena in Europe, opened in 1995 and has a capacity for 21,000 people, according to its website.

People present at the event included those who had come in from other parts of Europe.

(Editorial note: Content shared by users on social media has not been independently verified)

?Additional reporting by Tanveer Khatana and Ghulam Mustafa Mughal; editing by Haseem uz Zaman