A San Francisco transport official has been caught out in a leaked memo telling staff footage of a recent robbery spree was not being released to stop people making 'racial generalizations'.

The Bay Area's BART system has been rocked by at least three robberies in recent weeks, including one incident that saw about 60 young people board a train, rob seven people and attack two others.

Two other high-profile incidents saw a total of about 16 young people involved in the robberies, while locals reported seeing or hearing of many more.

Despite the robberies, BART Assistant General Manager Kerry Hamill explained why surveillance footage and other images were not being released in a memo sent to the board of directors.

San Francisco's BART transportation authority said it will not release footage of some recent robberies to ensure 'sweeping generalizations' about people of color are not made

'Disproportionate elevation of crimes on transit interfaces with local media in such a way to unfairly affect and characterize riders of color, leading to sweeping generalizations in media reports and a high level of racially insensitive commentary directed toward the District through our social media channels, email, and call centers,' the memo, obtained by KPIX, read.

The memo then explained how hard copies of the data compiled by BART was available in person at the local headquarters.

However, BART board member Debora Allen pushed back against the notion, asking why race was a factor in releasing footage.

'I don't understand what role the color of one's skin plays in this issue [of whether to divulge information]. Can you explain?' she wrote in an email to Hamill, obtained by KPIX.

BART Assistant General Manager Kerry Hamill (left) explained the decision in a memo, however it has been challenged by BART board member Debora Allen (right)

One of the recent robberies took place at the Coliseum stop, where about 60 young people boarded a train and stole from passengers

There have been at least three high-profile robberies in recent months. Pictured is the West Oakland BART station

The assistant GM then replied: 'If we were to regularly feed the news media video of crimes on our system that involve minority suspects, particularly when they are minors, we would certainly face questions as to why we were sensationalizing relatively.'

But Allen did not accept the explanation, firing back at Hamill: 'This is BART, people are sort of trapped in this train for awhile and they have a right to see what could potentially happen.

'What is the priority of BART? Is the safety of the passenger — of all passengers — is that a lesser priority than the race bias issue?'

A BART spokesman told KPIX California law protecting underage offenders prevented the release of video or images.