Why do rpm and yum commands not working due to an "error while loading shared libraries libbz2.so.1" ?

Issue

• yum and rpm commands are not working. The errors displayed are as follows.

# rpm -qf
rpm: error while loading shared libraries: libbz2.so.1: cannot open shared object file: No such file or directory

# yum list
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   libbz2.so.1: cannot open shared object file: No such file or directory

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.6.6 (r266:84292, Nov 21 2013, 10:50:32)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)]

If you cannot solve this problem yourself, please go to
the yum faq at:
  http://yum.baseurl.org/wiki/Faq

• sosreport can't be generated too.