Prosecutors say will appeal for longer Pistorius sentence

South African prosecutors said Thursday they would push for a longer sentence for Oscar Pistorius, describing his six-year jail term for murdering his girlfriend Reeva Steenkamp as "shockingly too lenient".

When he was sentenced earlier this month, Pistorius' lawyers said the Paralympic athlete would not appeal against the term, which was criticised by many activists as too short.

High Court judge Thokozile Masipa listed several mitigating factors for sentencing him to less than half the minimum 15-year term for murder, including the athlete's claim he believed he was shooting an intruder.

"The sentence of six years imprisonment, in all the circumstances, is disproportionate to the crime of murder committed (and) shockingly too lenient," the National Prosecuting Authority said in a strongly worded statement.

The NPA said the sentence was "an injustice and has the potential to bring the administration of justice into disrepute", adding that it would file papers to apply for leave to appeal on Thursday.

Celebrated sprint champion Pistorius shot Steenkamp, a model and law graduate, in the early hours of Valentine's Day in 2013, saying he mistook her for a burglar when he fired four times through the door of his bedroom toilet.