They look like low-lying, white or grey buttes, long, narrow hills with flat tops, barely a meter high.

When Ms Estemirova's colleagues walked into her flat last week they saw this photograph: five small bodies lying in a row, from five years down to nine months.

There is good evidence that if baby is given a bottle of formula while lying flat, the formula can get into the Eustachian tubes and middle ear and cause an infection.