The Estuary by Derek Gunn
In a small Irish town, a group of children trip over a mysterious object buried on the beach. It’s actually a long lost WW2 chemical weapon and now it is unleashed. Soon the peaceful town is a quarantine zone with no way out. And the townsfolk are infected and the infected are hungry. There seems no hope and no way out.
This is a good read, it’s nicely unsettling though the characterization is basic and there are more irritating spelling mistakes.