Teenagers mounted the roof of a Whangamatā cafe on New Year's Eve, throwing bottles at police who armed themselves with shields and batons.
Auckland woman Jane Phare is on holiday in the Coromandel town with seven teenagers, including her 15-year-old son, and had ventured out to check on the teens.
She said there were thousands of teens gathered on the streets. Some had climbed onto the roof of Blackies Cafe, next to the Whangamatā Surf Club, which is about 200m from her friend's bach she was staying at.
"There was just this roar of out-of-control drunk kids and no music," Phare said.