LIMA: There are some 300,000 children in Peru that slip through government social aid programs because they lack birth certificates, according to a recently-published World Bank report.

The figure represents 2.9 percent of the total population of minors up to age 17, according to the report published on Thursday.

The largest segment of the undocumented children -- 112,000 -- live in the Amazon jungle, in eastern Peru.

However a significant number -- 63,000 -- live in the overcrowded capital city Lima, according to the study.

There were several reasons the children were not registered, including costs involved in transportation and registration for humble families that live in remote communities. Some families also distrust the government.

The largest number of undocumented children are age five and under, the report said.

The World Bank proposes carrying out campaigns in areas where registration is low, reducing the registration costs and simplifying the issuing of identification documents.