They called me at 10:39am on 02/04/14. Discovered it's a land line in Southeast-ojus Eaea, FL (Miami, Dade). While this is in the US, the rule of thumb is to **NEVER** call them back as you could incur 'ring and run' charges. If it's important, and legitimate, the caller will call you back.
This appears to be reoccurring scam where criminals target people simply by calling them and allowing it to ring long enough to answer, then hang up. Our curiosity will get the better of us and we call them back determined to know who is was, was it important, and why they were so rude to hang up. Then when we get our phone bill, discover that we've been charged fees, sometimes less than $20, but other times in the hundreds... all because you called them back.