SARAJEVO (Reuters) - Relatives of victims of the Srebrenica massacre blasted the U.N. war crimes tribunal's verdict on Bosnian Serb leader Momcilo Krajisnik on Wednesday as too lenient, despite his sentence of 27 years' jail.

Families of some of 8,000 Muslims killed in the 1995 massacre by Bosnian Serb forces said they were outraged that the Hague-based court had acquitted Krajisnik of genocide charges and convicted him only of crimes against humanity.

"Yet another reward for the crime committed against us in Bosnia and Herzegovina, yet another disappointment," said Munira Subasic, the president of the Sarajevo-based association of Srebrenica mothers.

Krajisnik, speaker of the Bosnian Serb wartime parliament and right-hand man to wartime leader Radovan Karadzic, was found guilty of murder, extermination, deportation, persecution and forced transfer of non-Serb civilians.

He went on trial in February 2004 charged with genocide, complicity in genocide, crimes against humanity and violating the customs of war in the 1992-95 Bosnian war, in which at least 100,000 people were killed. He pleaded not guilty on all counts.

After the former UN "safe area" of Srebrenica fell to the Bosnian Serbs in July 1995, their troops intercepted thousands of Muslim men and boys and killed and buried them.

"Genocide was committed in Srebrenica and The Hague court confirmed that. All those indicted for genocide should be sentenced for it," said Sabaheta Fejzic, who lost her husband and only son in the Srebrenica massacre.

Bosnian Serbs called Krajisnik's acquittal on genocide charges "a great victory" but said his 27-year sentence was too harsh.

"They could not sentence him for genocide because there was no genocide in Bosnia," said politician Pero Marinkovic in Krajisnik's stronghold of Pale, echoing the often-heard Bosnian Serb denial of the Srebrenica massacre.

The UN tribunal has convicted two Bosnian Serb wartime commanders of genocide so far, both for aiding and abetting the massacre.

Subasic, who is still searching for her son and 20 other relatives who went missing in the Srebrenica slaughter, said that now she felt "even more humiliated".

She expressed the view of many of the bereaved that "soft" verdicts meant there was too little pressure on Bosnian Serbs to reveal the locations of mass graves.

"Judging according to these trials and sentences, I think I will most probably never find my son," she sighed in the small office of her association, after watching the broadcast of Krajisnik's sentencing on television.

Karadzic and his military chief Ratko Mladic are indicted for genocide over the Srebrenica massacre and the 43-month siege of Sarajevo. Both men are still at large after 10 years in hiding.