Violent crime is escalating in the Atlantic coastal regions and the Corn Islands, and the Nicaraguan National Police do not have the resources to combat it. The U.S. Embassy in Managua has received reports of numerous crimes against residents and tourists in the region and now prohibits personnel from traveling to the area, with limited exceptions. 
http://www.worldtravelwatch.com/05/09/nicaragua-violent-crime-in-atlantic-coastal-regions.html 
there is my source