Tegucigalpa, Honduras (CNN) -- The U.S. Peace Corps has pulled more than 150 volunteers out of Honduras while the organization reviews security in the Central American country, a spokeswoman said Tuesday.
The 158 volunteers attended a conference over the weekend and have safely left Honduras, spokeswoman Kristina Edmunson said in a statement. They have been placed on administrative leave while the Peace Corps evaluates the program, she said.
Honduras has the world's highest homicide rate, according to a 2011 United Nations report, which said there were 81.2 homicides for ever 100,000 residents in the Central American nation.
"It is unfortunate that in the country right now -- given the situation of insecurity, violence and crime that every day increases -- international organizations are pulling back their aid and personnel," said Migdonia Ayestas of the Violence Observatory at the the National Autonomous University of Honduras.
Honduran officials have said they regret the Peace Corps' decision to pull out volunteers, which officials announced late last month.
Before the volunteers left, President Porfirio Lobo told reporters that his government would keep working to fight the high crime rate in Honduras.
There are 5,000 volunteers from around the world working in Honduras, according to government statistics.
Akihiko Yamada, director of the Japan International Cooperation Agency in Honduras, said his organization was still sending volunteers but urging them to be cautious.
"They can't go to some areas," he said.
The Peace Corps also announced last month that it had canceled its January training classes for new volunteers in El Salvador and Guatemala.
"Peace Corps will continue to closely monitor and assess the safety and security climate and enhance support in these countries before making any further decisions," Edmunson said Tuesday.
Much like its neighbor to the north, Mexico, Central America is struggling to get a grip on violent crime. Drug cartels use the region as a strategic way station between South America, where most of the world's coca is grown, and North America, a major cocaine market.
Coca is the raw ingredient for cocaine.
The Peace Corps has operated since 1963 in Honduras and Guatemala, sending more than 5,500 and 4,800 Americans to serve in each country, respectively. It operated in El Salvador between 1962 and 1979, and returned in 1993.
CNN's Mariano Castillo contributed to this report.