Missing high schoolers found with relative

Three teenagers who went missing in southwest NSW have been found with a relative.

William Blake, Troy Klystra and Mitchell Cattle were found safe and well on Wednesday evening after disappearing from Yanco, near Griffith, the day before.

Police won't say whether the relative had found them and notified authorities or if the boys were with the relatives since they went missing.

The 15 and 16-year-olds were last seen at Yanco Agricultural High School about 9am on Tuesday.

Staff at the boarding school notified police of their disappearance about 7.15pm and a large scale search had been underway since.