Police are investigating after a man repeatedly approached young children in Dunedin offering them a ride in his car, in one case asking them to help look for a lost puppy.

Detective Sergeant Dylan Ross, of Dunedin, said the first approach of a primary school-aged child was reported in Three Mile Hill Rd last Tuesday.

He thanked a member of the public who intervened, resulting in the man driving away.

The second incident occurred this morning in Shetland St, Wakari, where a man asked another young child to enter his vehicle to help him look for a lost puppy, Det Sgt Ross said.

The child refused and the man again drove away.

Det Sgt Ross said in both cases the children ''did the right thing''.

"They did not get into the car and they told a teacher as soon as they got to school."

"We know that reports of incidents such as these can cause considerable concern for parents and other members of our community."

"We would urge everyone to be alert, not alarmed, and to take the opportunity to have conversations with your children about what they should do should they feel unsafe."

"This can be with a trusted adult, a teacher or Police."

The detective appealed for help from anyone who could assist with the police investigation into these incidents.

Dunedin police (03) 471-4800, Crimestoppers 0800-555-111.