The annual number of children who die before they reach age five is shrinking, falling to 7.6 million global deaths in 2010 from more than 12 million in 1990, UNICEF and the World Health Organization said on Wednesday.

Overall, 12,000 fewer children under age 5 die each day than a decade ago, the groups said in their annual report on child mortality.

Even in sub-Saharan Africa, where the burden of child mortality is greatest, the rate of improvement has more than doubled in the past decade, a sign that even the poorest regions can make progress, said Anthony Lake, executive director of the United Nations Children's Fund or UNICEF.

Despite the improvement, more than 21,000 children die every day from preventable causes, he said in a statement.

"Focusing greater investment on the most disadvantaged communities will help us save more children's lives, more quickly and more cost effectively," Lake said.

Between 1990 and 2010, the annual number of deaths in children under five fell to 57 per 1,000 births in 2010, from 88 deaths per 1,000 live births in 1990.

Even so, improvements in child mortality rates will not be enough to meet the United Nation's goal set in 2000 of reducing child mortality by two-thirds by 2015, and the groups say more money is needed.

"This is proof that investing in children's health is money well spent, and a sign that we need to accelerate that investment through the coming years," Dr. Margaret Chan, director general of the World Health Organization, said in a statement.

She said many factors are contributing to reductions in child mortality, including better access to healthcare for newborns, prevention and treatment of childhood diseases, access to vaccines, clean water and better nutrition.

"There is more attention being paid to what ensures health globally," Ian Pett, chief of Health Systems and Strategic Planning at UNICEF, said in a telephone interview.

For example, he said the government of Sierra Leone in April lifted all fees for child and maternal health, prompting a big improvement in child mortality rates.

"Many other countries are trying to do the same thing," Pett said.

Sierra Leone ranked among the top five countries seeing improvements in child mortality in the past decade, along with Niger, Malawi, Liberia and Timor-Leste.

About half of all deaths of children under 5 in the world took place in just five countries in 2010: India, Nigeria, Democratic Republic of Congo, Pakistan and China.

Babies are particularly vulnerable. According to the report, more than 40 percent of deaths in children under age 5 occur within the first month of life and more than 70 percent occur in the first year of life.

Deaths among children under age 5 increasingly are concentrated in sub-Saharan Africa and southern Asia, with 82 percent of child deaths occurring in these regions in 2010, compared with 69 percent in 1990.

In sub-Saharan Africa, one in eight children and in southern Asia one in 15 children die before reaching age five. That compares with 1 in 143 children dying before age 5 in developed countries.