Makeshift swastika and Nazi salutes spark outrage.

Newport Beach school officials on Sunday said they are investigating images posted on social media appearing to show a group of partying students — arms outstretched in a Nazi salute — gathered around red plastic cups arranged in the shape of a swastika.

Some of the people in the images are believed to be students or recent graduates of Newport Harbor High School, one official said. The other high schools in the district are Costa Mesa, Estancia, Early College and Corona del Mar.

The photos were allegedly taken this weekend at a party not affiliated with the school system.

Newport-Mesa Unified School District officials said they sent a letter to parents on Sunday.