(Reuters) - A teenage student was fatally stabbed at a Los Angeles middle school on Friday afternoon, officials said, with no-one yet taken into custody.

The 14-year-old victim, who was not identified by police, was on the David Wark Griffith Middle School campus around 3 p.m. local time when he was stabbed in the chest by another youth, the Los Angeles County Sheriff's Department said in a statement.

The victim was transported to a local hospital where he died, the sheriff's office said. The teen was a student at the nearby Garfield High School, and authorities did not know why he was at the middle school.

Local broadcaster KTLA reported that roughly 100 students on campus for after school activities were locked down for hours as anxious parents waited to pick them up.

No one has yet been apprehended and the investigation into the stabbing is ongoing, authorities said. Further details were not immediately available.

(Reporting by Curtis Skinner in San Francisco; Editing by Toby Chopra)