Three men and a woman have been arrested by police investigating an attack on a cab driver who had a knife pulled on him on a Bradford housing estate.

The incident, early last Saturday, was one of three in the Ravenscliffe area involving violence to cab drivers in a matter of hours.

Minicab firms in the area have since threatened to stop sending cars to the area until more is done to ensure the safety of their drivers.

Police have said they will step up patrols if necessary, and are offering safety advice to the companies.

A woman, 36, and a man, 20, were arrested earlier this week in connection with the alleged knife incident, which occurred at about 2.45am in Roundwood Avenue. Police today arrested two further men, aged 20 and 25.

Detective Inspector Richard Partis said: “We are aware of a number of incidents reported over the last year in the Ravenscliffe area in which taxi drivers have been the target of attacks.

"We take any reports of violence extremely seriously and will relentlessly pursue anyone involved in such intimidating behaviour.”

Cab firms in the BD2 area will meet on Monday to decide whether to boycott calls to Ravenscliffe.

Bradford East Liberal Democrat MP David Ward said: “I work quite closely with taxi firms and will be in Bradford on Monday to speak to them about this. I pay tribute to taxi drivers – it can be a dangerous job.”