Nearly 40 firefighters battled a wall of flame which swept across Devonshire Marsh yesterday.

And fire chiefs were probing the theory that vagrants burning rubbish on a nearby path sparked the fire, which took more than two-and-a-half hours to bring under control.

The blaze razed an area of more than 300 feet by 500 feet in the massive marshland area, a haven for rare plants and wildlife.

And nearby businesses were put on alert to evacuate their premises if the fire got out of control.

But yesterday Government conservation officer Dr. David Wingate said fire was nature's way of clearing the marsh and the plants were naturally fire resistant.

He said: "They will recover very quickly -- it looks bad at the time, but they will recover.'' But Dr. Wingate added: "Fire can be damaging to certain things, but in the long run, it favours the type of plants which grow in the marsh.'' Lt. Jon Thompson of the Bermuda Fire Service said the fire was a difficult one to fight and paid tribute to the 37 fire personnel who tackled it.

He added: "The wind was not in our favour and ground we had to work on was basically tufts of grass or reeds -- we kept slipping off them and into the marsh.'' And he said: "We stopped it spreading to the other side of the marsh -- I would like to congratulate them for a job well done under extremely difficult conditions.'' The fire, which appeared to have started on a path bordering the marsh behind Garden Market, was reported just before 2.30 p.m. At its height, a total of six fire engines plus support vehicles were at the scene and off-duty firefighters had to be called in to back up the duty crews.

Lt. Thompson added a warning for anyone intending to burn trash to take care.

He said: "If people are not sure of the vulnerability of the area they are in they should contact us for advice and we will be more than happy to assist them.

"It's not conclusive, but it appears to trash being burned by some homeless individuals which started the fire.''