28 Weeks Later is a 2007 post-apocalyptic horror film directed by Juan Carlos Fresnadillo, who co-wrote it with Rowan Joffé, Enrique López Lavigne and Jesus Olmo. It is the sequel to the 2002 film 28 Days Later. Synopsis: In the aftermath of a zombie-creating virus raging across Britain, NATO military forces salvage a safe zone in London, but two young siblings breaking protocol to find their infected mother, results in the reintroduction of the zombie scourge to the safe zone.

References:
https://en.wikipedia.org/wiki/28_Weeks_Later