A 22-year-old man has been arrested after a car crashed into a building in what police called a "serious collision".
A Renault Clio, the only involved vehicle, collided with a support pillar of Premier Stores in Llanwrtyd Wells, based on on the A483, just before 12.30am.
Police said the man was arrested on suspicion of aggravated vehicle taking without consent and careless driving.
The road has remained closed and police are appealing for witnesses to the incident.
A force spokeswoman said: "Police were called to the A483 at Llanwrtyd Wells at just before 12.30am to a report of a collision at the Premier Stores.
"A Renault Clio had collided with a supporting pillar at the store, causing structural damage.
"A 22-year-old man was arrested on suspicion of aggravated taking of a vehicle without consent, and careless driving.
"He, and another man, were taken to hospital with injuries.
"Road closures remain in place and a structural assessment will take place later today."
It is not known how severe the damage to the shop's structure is, and anyone with information is urged to contact Dyfed-Powys Police by calling 101.
Brecon Roads Policing Unit had previously tweeted about the incident at 9.45am: “Serious collision during the early hours in Llanwrtyd Wells currently being investigated.
“Single vehicle has collided with a building causing substantial damage. Appeal for witnesses to contact us on 101 quoting message number 002 of 24th January.”