The material stored in the USB stick pertained to the Swedish contingent serving with NATO in Afghanistan and an intelligence analysis of the attempted assassination of Lebanon's prime minister.

The Local reported Friday that the memory stick was found plugged into a public computer terminal at the library and was returned to military officials. It wasn't known if any library guests had accessed the files.

A military spokesman told reporters that "carelessness" with military secrets can result in the person responsible for losing them being sent to jail for up to six months.