About 145 coffins have been found buried under a high school in Tampa, Florida.

The coffins are believed to be part of a 20th century cemetery.

School officials believe the graves are part of Ridgewood Cemetery, a historic landmark of the poor people in the early 1940s that was owned by the city.

King High School opened in 1960. Officials began investigations last month after a person told a school board member about the location of the cemetery.

The coffins are buried 3-5 meters deep. For nearly two weeks the technicians used radar to confirm the location of the caskets.

In the cemetery may be the remains of more than 250 people, almost all of them African-American.