One young person is in a critical condition at Auckland City Hospital after a ute doing donuts rolled on a north Auckland beach.
Six other passengers - some of whom were perched on the back of the ute - have been taken to North Shore Hospital with moderate to minor injuries. Others were inside the ute's cab.
According to police, the 18-year-old driver fled the Rothesay Bay scene before returning.
Waitematā East Area Commander Inspector Sundip Patel said alcohol was a factor in the accident.
"This group has made some bad decisions which have been irresponsible and reckless, and as result seven people have been injured - one very seriously," he explained.
"I cannot emphasise enough the need to not take risks with lives when driving, and ensure others are not put in danger.
Insp Patel said beaches are not safe for driving because they are a "constantly changing environment".
The serious crash unit is investigating.