A 14-year-old boy suspected in a South Carolina schoolyard shooting last week faces a second murder charge after one of the victims died from his wounds, a prosecutor said on Monday.

The shooting was the latest in a series of rampages at U.S. schools that have fuelled debate over the extent of gun regulations in America.

A charge formerly filed as attempted murder was upgraded to murder after six-year-old Jacob Hall, who was shot during Wednesday's incident at Townville Elementary School in the northwest part of the state, died on Saturday, Solicitor Chrissy Adams said in a statement.

Hall's funeral was scheduled for Wednesday and will have a superhero theme.

Last week, the teen suspect was charged in the 10th Judicial Circuit court with one count of murder and three counts of attempted murder.

Authorities say he shot and killed his 47-year-old father as the man watched television at their home about three kilometres from the school.

He then drove to the school where he shot the students and a teacher, police said.

Adams, the South Carolina solicitor, also said on Monday that she filed new petitions for five individual counts of possession of a weapon during the commission of a violent crime.