Three-quarters of the world's small arms are held by civilians, with rapid and unchecked urbanization a key driver behind their proliferation, a Swiss academic study said on Tuesday.
Of the 875 million small arms in circulation, some 650 million or 75 percent are held by civilians, according to the study by the Geneva-based Graduate Institute of International Studies.
The US tops the list with 270 million small arms, which translates into roughly 90 firearms per every 100 people, the study said.
It also found that civilians are acquiring greater numbers of increasingly powerful guns, and that this trend is likely to continue for the forseeable future.
"The connection between per capita wealth and gun ownership is strong enough to suggest that as long as gun ownership laws are not changed, greater national wealth leads to greater gun ownership," the report said.
However, an equal problem is the growing poverty, violence and insecurity sparked by rampant urbanization in poor countries, where the drugs trade, availability of weapons and the opportunities for criminal gain make for a dangerous combination.
"Whereas urbanization used to be associated with industrialization and economic growth, this link has been broken," survey programme director Keith Krause said.
For example, Brazil's firearm homicide rate is greater than some war-torn countries, with the number of victims tripling to 21 per 100,000 from seven in the period 1982-2002.
Post-conflict societies also remain at risk from gun violence as many weapons still remain in circulation among the civilian population and societies often lack a robust regulatory and security framework, the report noted.