The Kamajor militia supported the government in the civil war
Sierra Leone's UN-backed war crimes court has more than doubled the prison terms of two former pro-government militia leaders during the civil war.
Judges said the original terms did not reflect the gravity of their crimes.
Moinina Fofana's sentence was increased to 15 years from six and Allieu Kondewa's to 20 years from eight.
The men led the Civil Defence Force that fought against rebels in the 10-year war in which some 50,000 were killed and many more maimed and raped.
The UN court originally convicted Fofana and Kondewa last year in what was a controversial trial.
The CDF recruited traditional Kamajor hunter militias to fight various rebel groups.
Correspondents say many Sierra Leoneans see the CDF as a force that fought for a noble cause, to defend the population against brutal rebel groups such as the Revolutionary United Front (RUF).
When the head of Kamajors, Sam Hinga Norman, was indicted five years ago there was public outcry. He has since died in custody.
The new decision on sentences was welcomed by Human Rights Watch, which said there was no excuse for attacking and mutilating civilians.
The Special Court for Sierra Leone was set up when the war officially ended in 2002 to try those people who bore the greatest responsibility for the atrocities.