The colombians raided a FARC camp on the 20th and killed a senior commander and a number of his men. Could be a case of the colombians finding some juicy intel that mentioned the individuals whose houses were raided.
If this is were the intel originated then why the search warrants? The FBI would not announce the warrants they would have tried to get someone on the inside. The only reason to raid is intelligence about a imminent attack or political motivation. We will learn which one it was in the near future.
FARC does have connections in the Democrat Party.