Firefighters appear to be getting the upper hand on a massive blaze that has destroyed much of an iconic Jersey shore boardwalk, after a last-ditch effort to slow its spread by ripping up boards that had not yet burned.

Authorities have not yet declared the fire under control but it appeared to have vastly lessened in intensity. Seaside Park mayor Robert Matthies said "it certainly looks like it's been suppressed".

The fire razed more than 30 boardwalk businesses in Seaside Park and Seaside Heights. No serious injuries were reported.

The turning point came as public works crews in Seaside Heights ripped out 25ft of the New Jersey boardwalk - which had just been rebuilt after Superstorm Sandy - and filled the void with sand piles to block the flames' advance.

Authorities say there is no immediate indication whether the fire, which broke out near a frozen custard stand in Seaside Park, was suspicious or accidental. An investigation is to get under way today.

Seaside Park borough councillor Nancy Koury says local business owners worked hard to recover from Superstorm Sandy's devastation and "now it's all gone".

"Haven't we been hit enough?" said Shirley Kreszl, who has rented a summer home in Seaside Park for decades.