'We want sauce' - police called over angry McDonald's mob

Police have been called to McDonald's restaurants across the United States after a PR stunt gone wrong.

The fast-food chain brought back it's rare Szechuan sauce for a one-day promotion on Saturday (local time).

However, McDonald's warned it would be a "really, really limited release" at only some stores, and they ran out almost instantly.

The sauce was originally only made in 1998 to promote the release of Mulan.

However, it was re-popularised after featuring in the science-fiction cartoon Rick and Morty.

Avid fans of the show drove for hours to get a taste of the sauce, and were left frustrated when they couldn't get their hands on it.

One couple shared that they had driven for four hours from Canada to get the sauce, but were left disappointed.

Crowds gathered around McDonald's counters in numerous locations, with angry customers chanting "we want sauce".

Police were called to the scene to manage the crowds.