Washington ? Almost 11 million children in developing countries die each year before the age of 5, most of them from causes that are preventable in wealthier countries, the World Bank said in a report released Sunday.

The causes include acute respiratory infection, diarrhea, measles and malaria, which together account for 48 percent of child deaths in the developing world, according to the report –called World Development Indicators.

“Rapid improvement before 1990 gave hope that mortality rates for infants and children would be cut by two-thirds in the following 25 years,” the report said. “But progress slowed almost everywhere in the 1990s.”

The report said only 33 countries were on track to reach the 2015 goal of reducing child mortality rates by two-thirds from its 1990 levels. It said only two regions — Latin America and the Caribbean and Europe and Central Asia — may be on track to achieve the target.

Five years ago world leaders outlined a number of development objectives, formally known as the Millennium Development Goals, to achieve by 2015. They include boosting primary school enrollments, removing obstacles to greater numbers of girls going to school and improving health care.

Many countries have made progress toward achieving the goals, but Francois Bourguignon, the bank’s chief economist, said: “I must admit many countries are off track and a huge effort is needed” to help them progress toward the 2015 goals. Some nations are more behind schedule than others, particularly in sub-Saharan Africa.

One section of the report tracks progress on all the indicators. It provides evidence that inequalities within countries — between rich and poor, urban and rural and male and female populations — may be as much a barrier to achieving the goals as inequalities between countries.

Worldwide, more than 100 million primary-age school children remain out of school, almost 60 percent of them girls.

“This situation endures despite overwhelming evidence that teaching children how to read, write and count can boost economic growth, arrest the spread of AIDS and break the cycle of poverty,” the report said.