Besides the immediate deaths, many people receive serious injuries which cannot be treated because of infrastructure damage and the survivors often suffer from depression, said the new study published in medical journal 'The Lancet'.

It also found that children are often at high risk from earthquakes which have caused over 780,000 deaths -- almost 60 per cent of all disaster-related mortality -- in the past one decade.

Other disasters, such as floods and hurricanes typically cause many deaths from drowning, but fewer injuries. But it is estimated that for every person killed in an earthquake, three others are injured, the BBC reported.

Many of the world's major cities, including Delhi, Los Angeles, Tokyo, New York and Shanghai, are on fault lines, putting millions of people at risk from earthquakes.

The study, which was led by Susan Bartel of the Harvard Humanitarian Initiative in Boston, also found that depression is very common following earthquakes -- affecting up to 72 per cent of the population.

Following the 1999 Turkey earthquake, 17 per cent of the population had suicidal thoughts, it found.

Children are often at higher risk of injury and death during earthquakes than adults. In Haiti in 2010, 53 per cent of patients were younger than 20 years old and 25 per cent were under five, the study found.

"Because earthquakes frequently affect populous urban areas with poor structural standards, they often result in high death rates and mass casualties with many traumatic injuries," the researchers wrote.