A study in El Salvador says 22 percent of small businesses in the Central American country have been victims of extortion by street gangs.

El Salvador's Foundation for Economic and Social development says the study involved almost 4,000 business operators.

The study says 59 percent of those who reported being victims of extortion said it involved gangs demanding regular protection payments.

Researchers also found that almost half of the businesses surveyed reported some type of crime against them.

Largely because of street gang violence, El Salvador recorded one of the highest homicide rates in the world last year, though killings have dropped recently.