At least four Nigerian soldiers are killed in an ambush . The assets provide some of the best tools to try to find the girls , but the Nigerian government has shown some reluctance to use U.S. help . Kidnapping of schoolgirls an `` unconscionable crime , '' says Kerry . May 14, 2009 -- The U.S. State Department issues a travel warning for Nigeria and warns Americans to avoid traveling there. Concerns about intelligence sharing and civilian deaths complicate the situation .
At least four Nigerian soldiers are killed in an ambush . Kidnapping of schoolgirls an `` unconscionable crime , '' says Kerry . May 14, 2009 -- The U.S. State Department issues a travel warning for Nigeria and warns Americans to avoid traveling there. Concerns about intelligence sharing and civilian deaths complicate the situation .