Dorset and Wiltshire Fire and Rescue received a call about the "gas related incident" shortly after 09:50 BST.
The homeowner, who was in the house at the time, has been taken to hospital.
Residents reported hearing a "big boom" and an air ambulance landed near the scene.
The internal walls of the flat appeared to have been blown out in the blast.
Roads leading to the area have been closed by police.
An ambulance, air ambulance, critical care car, operations officer, and doctor were sent to the scene.
One patient was taken to Southampton General Hospital by land ambulance.
SGN is working closely with the authorities to determine the cause of the incident.
LONDON DAILY ARCHIVE
Gas Explosion at Bournemouth Home Leaves One Injured and Roads Closed
A person has been taken to hospital after a suspected gas explosion at their home on Gunville Crescent in Bournemouth.
06 June 2023 · 11:28 UTC
