Ubuntu: Some index files failed to download

Symptom:
When running sudo apt-get update got the following error:

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-backports/universe/i18n/Index  No Hash entry in Release file /var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-backports_universe_i18n_Index

E: Some index files failed to download. They have been ignored, or old ones used instead.

Solution:

sudo rm -rf /var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-backports_universe_i18n_Index
sudo apt-get update