Police are looking for perpetrators involved in two separate armed robberies in the Waikato yesterday.

Police dogs are involved in the search for a man who used a shotgun to demand money from a dairy in Ngaruawahia at around 11am yesterday morning, but they've had no luck tracking him down yet.

In Hamilton, police are still looking for two men who used knives to rob a food store on Hukanui Road.

The pair brandished the knives, before making off with cash and cigarettes.

Police investigations into both incidents are ongoing.