Hundreds of dead snapper have washed up on Coromandel beaches on the North Island of New Zealand, leaving holidaymakers perplexed.

The mysterious incident came as the southern United States was hit with a second unexplained mass bird death within a week.

Horror haul ... dead fish floating and washed up on the Coromandel Peninsula.

People at Little Bay and Waikawau Bay, on the north-east of the peninsula, were stunned when children came out of the sea with armfuls of the fish and within minutes the shore was littered with them.

Charlotte Pearsall, whose family have lived at Little Bay for the last 30 years, said she had never seen anything like it.