JOHANNESBURG, South Africa (AP) _ A white police captain is sentenced to death in South Africa for killing 11 blacks. Four police officers in Guatemala are jailed for beating a child to death. Chinese leaders order a crackdown on police torture.

These and other recent cases underline a changing attitude in some parts of the world toward human rights abuses by security forces that once would have been ignored or condoned. The anger that greeted the Rodney King verdict in Los Angeles has been matched in other nations.

While torture and killings continue under many authoritarian regimes, some human rights activists say growing demands for reform are aiding efforts to curb abuses.

Public outrage over the fatal police beating of a radical student in South Korea in April 1991 set off seven weeks of violent nationwide protests.

''Police brutality may be as serious as in the past, but people are more enlightened and more aware of the problem,'' said Kim Sang-chua, a human rights lawyer in South Korea. ''The public is less tolerant'' of abuses.

In Britain, the overturning of convictions against 17 people in Irish Republican Army bombing cases since 1989 has raised questions about the impartiality of the police and the courts.

''Over the last 10 years, confidence in the police has certainly declined,'' said sociology Professor Janet Foster of the University of Warwick. ''Public tolerance toward perceived police violence has certainly decreased.''

The end of the Cold War, the demise or weakening of some repressive regimes and international support for human rights are adding to pressure to end abuses in different parts of the world.

Human rights groups are springing up to combat repression and demand accountability from governments and their security forces.

A South African judge Thursday sentenced former police Capt. Brian Mitchell to hang for the 1988 killings of 11 blacks in a political power struggle. Four black officers received long jail terms in the first case in South Africa of police being found guilty of a mass killing.

Professor S.A. Strauss, a legal expert at the University of South Africa, said the case reflected a changing political climate as apartheid ends and people push for greater freedom.

''The public in the past was perhaps overly forgiving to the police. Police brutality was tolerated by members of society - white society in particular,'' he said.

''Many people now realize that police brutality constitutes a danger to the hopes of a better society.''

Democratic governments in Guatemala and El Salvador have curbed security force abuses, punishing military and police officers in a way that would have been unthinkable a few years ago.

In Guatemala, where a human rights ombudsman was recently appointed, four police officers were sentenced to long prison terms last week for the murder of a street child.

Western governments and international rights groups are aiding campaigns for reform. Western donors have warned some African nations that vital aid will be cut off if abuses are not ended.

Chinese leaders recently ordered a crackdown on police torture during interrogations ''to strike back at international forces that are using human rights to attack China's socialist system.''

In many areas, activists acknowledge making little progress. Human rights groups in Israel, where security forces have been accused of abuses, say they have far to go.

''If we weren't here and other human rights activists weren't here, then things would become much worse,'' said Naama Yasuvi of the Israeli Information Center for Human Rights in the Occupied Territories, formed by liberal Israeli academics and politicians.

While the press and the public in the former Soviet Union no longer accept state repression as a fact of life, activists say rights violations are still common.

''We've made progress, certainly. But it's still too early to say that we have an effective system for monitoring and defending human rights,'' said Lev Timofeyev, a former political prisoner.