At least 22 people were hospitalized after an explosion erupted on a London Underground train Friday. Pictures and videos from the incident went viral, but not all of them were authentic.

One phony video, which was posted to Twitter Friday, shows more than a dozen people on the side of the road. The blurry footage appears to show an explosion on the pavement. Authorities caution bystanders to move back. “At least 20 injured after an explosion in the London Underground Parsons Green station,” the caption written by netizen Fabian Ciobanu read.

Even though the explosion occurred at 8 a.m., a Facebook video claimed to show the blaze at night. “In The Video: Flames glowing from a massive explosion on a London Underground train in Parsons Green station. #London police declared this as terrorist incident.’ #LondonBlast,” the caption said.

The blast occurred during rush hour. “The train was packed, and I was down the other side of the carriage standing up, looking at my phone and then I heard a big boom and felt this heat on my face,” Natalie Belford, 42, a hairdresser who was on the train, told the New York Times. “I ran for my life, but there was no way out. The doors were full of people and the carriage was too packed to move down.”

London
A terrorist attack on a London Underground train left at least 22 people hospitalized. Some fake videos claimed to show the explosion. Getty Images

The explosion Friday marked the fifth time Britain was attacked in 2017. There was an automobile and knife attack near Parliament in March, a suicide bombing at an Ariana Grande concert in Manchester in May, a van and knife attack near London Bridge and a van attack close to a London mosque. The last two incidents occurred in June.

The attack was declared an act of terrorism. “Deputy Assistant Commissioner Neil Basu, the senior national coordinator for CT policing, has declared it a terrorist incident,” police said in a statement, according to The Express. “Officers from the Metropolitan Police Service and British Transport Police attended the scene, along with colleagues from the London Fire Brigade and London Ambulance Service. At present we are aware of a number of people who have suffered injuries.”

President Donald Trump claimed London police knew the about the people responsible for the terrorist attack. “Another attack in London by a loser terrorist. These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!” he tweeted Friday. “Loser terrorists must be dealt with in a much tougher manner. The internet is their main recruitment tool which we must cut off & use better!”

Prime Minister Theresa May said the attacks were “cowardly.” She responded to the POTUS' criticism by saying: “I never think it’s helpful for anybody to speculate on what is an ongoing investigation.”

London Mayor Sadiq Khan took to Facebook to condemn the Friday attacks. His full statement has been shared below:

“The Metropolitan Police have confirmed that the explosion on a train at Parsons Green Station this morning is being treated as terrorism.

“Our city utterly condemns the hideous individuals who attempt to use terror to harm us and destroy our way of life.

As London has proven again and again, we will never be intimidated or defeated by terrorism.

“I am in close contact with the Metropolitan Police Service, Transport for London, Government and other emergency services who are responding at the scene and leading the investigation. I will be attending the emergency COBRA meeting in Whitehall this afternoon with the Prime Minister.

“My sincere gratitude goes to all our courageous emergency responders and the TfL staff who were first on the scene.

“I urge all Londoners to remain calm and vigilant, and to check Transport for London's website for travel advice.”

Follow me on Twitter @mariamzzarella