WA search for missing Korean woman

A search is underway for a Korean woman missing south of Perth.

Police say Kim Hyun-su, 62, hasn't been seen since leaving to go bushwalking in the Wannanup area about 11.30am on Tuesday.

They say she arrived in Perth from Korea the previous day and was staying with her son.

Ms Kim is thought to have been heading along Caspian Drive, walking towards Northport Boulevard.

She is unfamiliar with the area, does not speak English and is unlikely to attempt to speak to anyone trying to help her.