A passenger jet plunged 8000m in five minutes, injuring 26 people, in what was described as "brutal decompression" during a flight from Britain to Spain.

The Boeing 737, run by budget airline Ryanair, was carrying 168 passengers and seven crew from Bristol to Barcelona when the incident occurred.

Rescuers reported passengers as saying they were terrified when the plane plummeted and oxygen masks dropped.

The plane landed at Limoges in France about 7.30am AEST as a "safety precaution", Ryanair said.

Some 26 passengers were taken to hospital with ear problems, the airline said.

Emergency services said the ear problems were all minor.

Police said the jet came down 8000m in five minutes but an initial inspection of the plane had not revealed any causes for the depressurisation.

Ryanair sent another aircraft to Limoges, which left at 11.30am with 127 people who wished to immediately continue their journey.

The remaining passengers were expected to continue on later today.

The Australian