Forty million children live on the streets. Twelve million children die each year before the age of 5, mostly from preventable diseases. Some 250 million are forced to labor for long hours and low pay.

As if those horrors were not enough, says a British human rights group, 2 million children have died in wars over the past decade, 6 million have been seriously injured or disabled and almost 30 million have become refugees.

Figures from aid agencies show that despite an all-embracing U.N. treaty protecting children, their rights are being increasingly ignored, Index on Censorship said in a report to be published April 2.

The 7-year-old U.N. Convention on the Rights of the Child is the most widely ratified human rights treaty in history, yet most of the evils it promised to remedy have worsened, said writer and broadcaster Caroline Moorehead, who carried out a study of the convention for the London-based group.

The convention has become "something of a sham" and is violated "systematically and contemptuously" by many countries, she wrote. "No countries violate it more energetically than those that were quickest to sign.

"Reports pour out daily - on female circumcision, land mines, prostitution. For the most part they have a sad and defeated ring to them."

According to UNICEF, the United States is among only six countries that have not ratified the convention. Under it, all children have the right to be protected against all forms of abuse and exploitation and to develop physically and mentally to their full potential.

Index on Censorship compiled statistics from a number of agencies, including the U.N. Children's Fund, the British charity Save the Children and the Children's Defense Fund of the United States.

Africa is the continent where children learn about war, Moorehead said.

Uganda, Burundi, Zaire, Somalia, Angola, Mozambique, Liberia and Sudan have all experienced civil wars in which children as young as 7 have been coerced into fighting, despite the convention's ban on children under 15 becoming soldiers.

In the turbulent west African state of Liberia, one-third of soldiers are believed to be children. "Biddable, frightened, dependent, they make excellent killers," Moorehead said.

In the central African country of Rwanda, ethnic conflict has separated 100,000 children from their parents, said Moorehead. Most are aged between 2 and 8.

In Asia, where one quarter of the world's children live, youngsters learn about hard work. India has between 60 and 115 million child workers, 15 million of whom are "bonded" child slaves working off their family's debts.

One million children work in the continent's sex trade.

Of the world's homeless children, 7.5 million live and work on the streets in Brazil, according to estimates by UNICEF.

In Brazil, nearly half of children live below the poverty line, estimated at dlrs 60 a month, said Index on Censorship spokeswoman Julia Vidal-Hall.

Youngsters living on the streets of Latin America are increasingly targeted by vigilantes; in 1992, six street children were murdered every day in Colombia.

Children suffer in rich countries, too.

The U.S. lobby group, Child Welfare League of America, reports that one child in five in the United States lives below the poverty threshold, which the government puts at dlrs 7,761 per person per year. Among black children, the figure is 44 percent.

Britain's Child Poverty Action Group says one in three now lives in poverty, compared with one in 10 in 1979. The lobby group estimates poverty at 50 percent below average earnings, giving 206 pounds (dlrs 330) a week for a couple with three children, excluding rent.