More than a third of children in Indian cities suffer from malnutrition, according to a report by the UN's World Food Programme (WFP).

The urban poor are most at risk

The study says that 36% of urban children were shorter than they should be and 38% were below their normal weight.

"Despite a surplus of food, there are a great number of people who suffer from malnutrition or in some cases famine," WFP special representative Mohammed Zejjari told Reuters.

The report follows an earlier one which focused on the situation in rural areas, and both are designed to give the Indian authorities an overview of where the most serious problems were.

Urbanisation

The report highlights in particular the increasing phenomenon of migration from rural to urban areas, often as a result of drought or flooding in the countryside.

It said that once they arrived in the cities, unskilled and illiterate people from rural areas could not afford decent food.

And it said that while there were many malnourished Indians in cities such as Delhi and Bombay, the problem was often worse in the smaller cities and towns where there were fewer jobs and resources were scarcer.

The study also cited other factors as contributing to the plight of the urban poor such as improper sanitation, contaminated drinking water, and urban pollution.

It said these all contributed to the breeding of diseases which, for people already weakened by poor nutrition, were difficult to resist.

Mohammed Zejjari said India needed to tackle the increasing casualisation of the unskilled workforce to ensure they had more buying power to feed themselves.

And he said that in the meantime, those worst affected should get short-term food aid.

India is the world's second most populous nation, with more than a billion people.