Police officers swooped on a city-centre squat as they investigated two break-ins at a Norwich supermarket.

Officers searched Imperial House on Rose Lane, where they found property believed to be linked to break-ins at the Farm Foods shop in Westwick Street, and arrested a 23-year-old man on suspicion of drug possession.

The disused office building, which has lain empty for several years, has been occupied for the past fortnight by a group of around 20 squatters, who are being taken to court by the building owners Aviva.

The group, made up of men and women aged 16 to 28 from countries including Lithuania, Poland and Ireland, claim they are occupying the building legally and have not caused any damage.

Police arrived at around 1pm today, investigating two burglaries at Farm Foods on Saturday and Monday, when burglars forced entry to the building and stole several items of food.

One of the squatters, Louis, who asked only to be identified by his first name, said many of the young people were 'vulnerable' and felt they had nowhere else to go.

'If people didn't have places like this then their situation would be much worse. When we occupy somewhere like this we do it legally. We pay all our own bills, and we don't cause any criminal damage.'

The group has a one-strike policy, he said, where members accused of an offence were given a warning and a chance to repair the damage, and expelled from the group if it happened a second time.

Many of the offices within the five-storey building have been converted to makeshift bedrooms.

Louis added that members of the group helped with charities and arts projects, and were given food handouts from sandwich shops and cafes to sustain them.

An Aviva spokesman said the company was pursuing court action to remove the squatters from Imperial House, and had served them with court papers.

'Squatters are currently occupying Aviva's property and steps are being taken to recover possession of the property as soon as possible. The squatters are aware of the court proceedings,' he said.

A police spokesman said officers had been making enquiries in relation to the burglaries.

'The building was searched and property, believed to be stolen from this burglary, was seized. While at the scene officers arrested a 23-year-old man on suspicion of drug possession after he was found with cannabis. He remains in custody at Wymondham.'