These scammers left a message saying that a loan
had been approved, and one only needed to call them
in order to make the loan effective.

Since I had not applied for any loans I became suspicious.
When I called them they wanted all kind of personal
information. They were unable to locate "my loan" approval
using the telephone number they had used a few minutes earlier.
Therefore this appers to be an scam to get your personal
information, or to make you apply for a (small) loan.
In the latter case I would be concerned about their fees.
 Sep 17th, 2014