Heavily-armed cops surround house for hours

Heavily-armed police surrounded a house north of Adelaide in a major operation today.

Police initially responded to concern's for a person's welfare inside a MacDonald Park home about 11.30am.

Dozens of specialized officers converged on Elwood Road property investigating reports of a firearm on the premises.

Patrols cordoned off the street and spent a number of hours negotiating with people inside.

A woman who emerged from the home just before 3pm was taken to a police car.

Soon after a man was detained by police and questioned in the back yard of the home.

Police alleged they found 7kg of cannabis and hydroponic equipment on the property.

The man was summonsed to appear before court at a later date.