Here again, I'm highlighting changes in yellow.  Re the sentence starting with "A bulletin..." I actually added the "caution" part, thinking that maybe the original did have this implication since it makes sense, but if this wasn't actually part of the original, you could instead put "advising that military personnel can be easily recognized"...:

US-soldiers in danger at home: The FBI warned the Army of attacks by supporters of the terror group "Islamic state" shortly after the US had expanded its air raids against the jihadists.

Washington – The FBI has warned the US military of possible attacks on American ground soil by the terror group "Islamic state". A bulletin was released for the holiday season, advising caution, since military personnel can easily be recognized while traveling by their uniform, CNN reported on Monday. The network referred to information from an anti-terror official.

According to the information, the IS is looking for "like-minded individuals in the US in order to carry out the attacks." Apparently, members of the IS are specifically searching Twitter, Facebook and similar networks, using social media messages that express support for the group as leads.

The bulletin, CNN said, calls on US-soldiers to check their communication for messages that "could attract the attention of violent extremists".