"There has been a significant drop in the number of child marriages worldwide, the United Nations children's agency says.
Unicef estimates that 25 million child marriages have been prevented in the past decade.
One in five girls are now married before they are 18, compared with one in four a decade ago.
South Asian countries have seen the biggest reduction in child marriages, Unicef says.
In India this was achieved by better education for girls and by publicizing the harm child marriage causes."