By Anastasia Moloney

BOGOTA, June 1 (Thomson Reuters Foundation) - Guatemalan police have rescued 22 children - some working 16-hour days making corn tortillas - as part of a crackdown on widespread child labour in the Central American nation, according to public prosecutors.

Police arrested six people on charges of child labour on Wednesday, following 37 raids on shops and food stalls in the capital Guatemala City.

The children rescued were aged 14 and 17, and most came from impoverished indigenous communities in rural areas.

Children were forced to work seven days a week in unhealthy conditions, and with little pay and food, prosecutors said.

The police raids aimed to target "those whose take advantage of a child's vulnerability to get cheap labour," the public prosecutor's office said in a statement on Wednesday.

Poverty drives child labour in Guatemala.

About half of Guatemala's 15 million people live in poverty and the country has one of the world's highest rates of chronic malnutrition, mostly affecting the children of indigenous communities.

To put food on the table, some parents encourage their children to quit school and work in the capital, leaving them open to sexual exploitation and forced labour, experts say.

Nearly 415,000 children, some as young as seven, work in Guatemala, according to the U.S. government.

Most child labour exists in agriculture, along with domestic work, forced begging and garbage scavenging.

It is common to see children working day and night as shoe shiners and street vendors on the capital's streets.

Worldwide there are 168 million children in child labour, according to the International Labour Organization.

The United Nations has a global goal to end all child labour by 2025 and to eradicate forced labour and slavery by 2030.

(Reporting by Anastasia Moloney @anastasiabogota, Editing by Lyndsay Griffiths. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights, climate change and resilience. Visit http://news.trust.org)