Police said the increased presence was necessary after shots were fired in three parts of Nottingham in the past week.

Nottinghamshire Police has also sent out more armed vehicle patrols across the county as part of an on-going crackdown on gun crime.

The last two incidents happened on Monday night in the Meadows and Aspley areas of the city.

Mr Welch: Criminals are firing at each other

Police said at least four shots were fired after a minor car accident in the Meadows.

A few hours later shots were fired at Roker Close in Aspley. No-one was hurt in either incident.

Last Tuesday, a school-bus driver narrowly escaped injury after shots were fired near Djanogly Technical College in Sherwood Rise.

Shattered windscreen

Shots were fired from a car after a chase through city streets.

The gunshots shattered the windscreen of the bus, which was in the school car park.

The driver, who was the only person on the bus at the time, was shocked but not injured.

Assistant Chief Constable Martin Welch said: "We've had a number of incidents where armed criminals trying to sort out their own disputes have fired shots at one another, and obviously there is an issue of public safety."

Neigbourhood Watch co-ordinators in the city have backed the decision to use more armed patrols.

Don Reid, who runs a Neighbourhood Watch in the Lady Bay district, said prompt action was needed to catch those who use firearms.