A human rights group says Rwandan police have killed some 20 detainees since November, part of a rising trend of deaths in police custody. As Nick Wadhams reports from Nairobi, the killings may be a sign that a recent government initiative meant to stop the killings of genocide survivors is backfiring. Nick Wadhams reports from Nairobi.

 New York-based Human Rights Watch says in a report Thursday that the killings undermine Rwanda's efforts to enforce the rule of law 13 years after the spate of anarchic violence in which some 800,000 Tutsis and moderate Hutus were killed in 1994.

Human Rights Watch says it fears the killings are a consequence of a poorly defined government policy that is aimed at reducing attacks on survivors. The policy says that says all Rwandans must be responsible for each other's safety.

Now, there are fears that police are using the new government policy to abuse and kill prisoners being held both on genocide charges and on charges of crimes including rape and murder.

Alison Des Forges of Human Rights Watch has been investigating rights issues there since before the genocide.

"These are not positive developments," Des Forges said. "Given that Rwanda is so concerned about trying to maintain social order, trying to establish a rule of law, we're saying look you have some rules here and you have to obey them and difficult as the situation may be, and certainly no one would say that it's an easy situation, it's not going to be improved by ad hoc measures that do not follow the laws that you have put into place."

The killings underline the tensions that remain in Rwanda 13 years after the genocide. Several human rights groups have noted an increase in attacks on genocide survivors and people involved in a community justice system called gachacha that handles some genocide cases.

Many of the killings took place in areas where the genocide was particularly brutal or where genocide survivors have been targeted. Des Forges says she fears the consequences if the killings are not controlled.

"If these reasons of continuing tension and hostility are not dealt with in an orderly and systematic fashion they will perhaps grow larger, and that could pose a serious long term danger so what we're assaying is the problem needs to be recognized, that I think has already happened and that's positive but then it needs to be dealt with in a manner according to law, orderly and transparently. And not by some administrative policy of collective responsibility," Des Forges said.

Rwandan officials could not immediately be reached for comment. But a government statement included with the report said investigations into the killings are underway.

Rwanda has argued that the prisoners were killed trying to overpower their guards and escape from prison. But Human Rights Watch says it is skeptical about that claim in part because attempts to escape prison in Rwanda have been rare in the past.

The government statement may reveal more than the government intended. As Human Rights Watch notes, it calls the slain suspects killers who were ready to die for their genocide ideology, though they were never convicted in trial.