Police started Operation Real Estate last year

Deputy Chief Constable Sean Price said: "It is a problem that is faced by every major city in the UK, but we are one of the most successful in dealing with this, which makes the streets of Nottingham safer than many others."

"It is not an issue about Jamaica or a race issue - it is about criminals coming into Nottinghamshire to commit serious crimes and we are dedicated to stop that," he said.

Of the 400 people arrested, 47 were Jamaican nationals held in connection with attempted murder or drugs and firearms offences.

Rival gangs

Forty-one other Jamaicans have been deported for questioning about serious crimes in Jamaica.

A further 12 are appealing against deportation or their cases are being further investigated.

Nottinghamshire police are trying reassure the city's Jamaican community that the arrests are not being made at random.

The arrests come after months of armed patrols in the St Ann's and Meadows areas of the city, where there have been a series of drug-related shootings in the past two years.

Operation Real Estate involves officers who operate in pairs, spending up to five hours from dusk until midnight patrolling the streets.