Does anybody remember the scene in the cemetery in *Resident Evil: Apocalypse* (2004)?

The group of survivors walked through the cemetery.

While Alice explained about the virus, the dead man got out from the grave and then attacked the reporter. And all the other dead men raised as zombies from their graves. How could this happen? They were buried. I suppose that nobody had bitten them. May be the land has already been infected?

![enter image description here](https://i.stack.imgur.com/0NaR9.png)