Teen missing from NSW beach for 24 hours

The search for a teenager missing at an unpatrolled NSW north coast beach is expected to continue for a third day on Monday.

The search for a teenager missing at a NSW North Coast beach will continue on Sunday morning. (AAP) Source: AAP

A 17-year-old boy is still missing more than 24 hours after he got caught in a rip at an unpatrolled NSW north coast beach.

Ali Mosawi, 17, was swimming with a group of people at the isolated Pebbly Beach, in the Yuraygir National Park, when they got into trouble about 3pm on Saturday.

Police say three of the group managed to swim to shore and helped a fourth boy to safety.

Mr Mosawi, who is not thought to be a strong swimmer, could not be seen.

Searches during Saturday and Sunday, involving police divers, PolAir, Surf Live Saving NSW volunteers and the Westpac Lifesaver Helicopter, have failed to find the teenager.

Some of his friends have started posting messages of grief on social media while others say they want him to "come back home".

Mr Mosawi's disappearance came a day after a man in his 20s drowned in a rip at Palm Beach on Sydney's northern beaches.

Police say the search for Mr Mosawi will resume early on Monday.