Hampshire Fire and Rescue Service said the fire broke out at the 15-storey Shirley Towers in Church Street shortly after 2000 BST on Tuesday.

A further two firefighters suffered minor burns to their hands in the incident and were taken to hospital.

Chief fire officer John Bonney said the death of the two firefighters had left "a devastating hole" in the service.

A spokesman for the fire service said the identities of the killed firefighters would not be released until their families had been informed.

An investigation into the fire, which was thought to have started on the seventh floor of the building, is being carried out by police and fire officers.

The building, which is one of Southampton's tallest, was evacuated of residents who were provided with emergency accommodation by the city council.

Nearby roads were cordoned off by police as up to 20 fire engines were called to the scene and firefighters from neighbouring counties were called in to help.

Mr Bonney said it was an "incredibly difficult and sad time" for the fire service.

'Incredibly difficult'

He added: "Our thoughts and prayers are with their families at this tragic time and we are giving them all the support we can.

"This is not only a devastating loss to our service but is a loss to the whole fire service community.

"During these incredibly difficult circumstances, firefighters at the scene undertook the successful evacuation and rescue of a number of people.

"Their professionalism, under truly difficult conditions, has been admirable and a testament to our service."

A joint police and fire service investigation into the cause of the fire is under way and the Health and Safety Executive has been informed