South Korean police on Tuesday were questioning an elementary school teacher who allegedly stabbed a first-grader to death in the city of Daejeon.

The teacher confessed to the crime after police officers found her and the young girl with stab wounds at the elementary school, local media reported.

A teacher at a South Korean elementary school has admitted to stabbing a seven-year-old girl who was found in cardiac arrest and later died in hospital, a police official said on Tuesday.