What happens when a Ford Fiesta slams into a security barrier? Thankfully not much, as one suspected terrorist found out, but a group of cyclists between the car and Parliament wasn’t so lucky. Several were injured in what appears to be an intended terror attack using the car as a weapon:

Metropolitan Police have arrested the driver of a vehicle after he crashed into the barriers outside British Parliament in London and are holding him on suspicion of terrorist offenses.

The police confirmed only one person was arrested, the driver, after the accident at about 7:37 a.m. local time. No one else was in the vehicle.

Police also said a “number” of pedestrians were injured. The London Ambulance Service said two people were taken to the hospital, but their injuries are not considered serious.

NBC News got video of the arrest:

A man has been arrested and several people injured after a car crashed into barriers outside the UK Houses of Parliament. https://t.co/9zBNvqdE6G

Credit: @VinnyMcAv @euronews pic.twitter.com/851EIM0BVU

— NBC News (@NBCNews) August 14, 2018

The police announced that they will investigate this as a terror attack, while “keeping an open mind” on intent:

While we are keeping an open mind, the Met's Counter-Terrorism Command is leading the investigation into the #Westminster incident.

— Metropolitan Police (@metpoliceuk) August 14, 2018

Thus far, reports the Guardian, not much is adding up in the case:

The man, in his late 20s, was arrested at the scene and taken to a police station in south London where he remains in police custody. He was the only person in the vehicle, which remains at the scene and is being searched. No weapons were recovered, according to police.

Speaking outside New Scotland Yard, Neil Basu, the head of counter-terrorism policing in the UK, said officers were working to get more information on the suspect but he was not cooperating. The man was not known to the security services, he said.

“Given that this appears to be a deliberate attack, the method and this being an iconic site, we are treating it as a terrorist incident,” said Basu.

The UK had locked down central London in case this was a prelude or feint attack, but by now things are returning to normal. Parliament has announced that tourist operations will continue today, even with police still cordoning off some traffic. The phlegmatic Brits will demonstrate that terror attacks won’t frighten them into submission, if in fact that’s what this is.

And it certainly looks like a terror attack, but its futility has to raise some questions. Using cars as weapons has become a familiar tactic for Islamist terrorists in Europe and the US, but not necessarily for attacking well-defended buildings. For an attack like that to succeed, one would need a much heavier vehicle than a lightweight compact. Why not rent a moving van? For that matter, why not load up the car with explosives, or carry other weapons? Previous car attacks have resulted in knifing sprees once the car crashed.

Perhaps this is just an unstable idiot who conducted this attack on the spur of the moment. Or maybe he’s a pawn being used to test defenses and responses. (Actually, “unstable idiot” seems like a good bet either way.) London police will have to find out quickly whether this is part of a larger plan, or merely a good opportunity to get one nut off the street for good.