Zambian health authorities on Monday started the country's first-ever vaccine campaign against diarrhoea on children under five years of age, in an attempt to reduce deaths arising from the disease.

The minister of mother and child health, Joseph Katema, administered the vaccine to children in Lusaka's Chawama slum.

"This just marks the beginning of the vaccination exercise, it will not only be in Lusaka but is a countrywide programme," Katema said.

According to the UN children's agency UNICEF, is the second biggest killer of children in the world.

Zambia's government says diarrhoea contributes to the deaths of 40 children each day, or 15,000 deaths annually.