Officers are keen to identify the man pictured after racist language was used on a bus in St Albans.
The incident occurred on Thursday, June 15, between 3.45pm and 4.30pm, on the Arriva 301 bus which travels from St Peters Street towards Stevenage.
It is reported that an individual made racially offensive comments while travelling on the bus.
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"Our enquiries are continuing, and we are appealing for anyone with information to please come forward," said PC Ryan Coyle, investigating.
"We are releasing this image because we believe the individual pictured was in the area at the time and may have information that could help our enquiries.
"Were you travelling on the bus at this time and saw what happened, or do you recognise the person pictured? Additionally, if you are the person pictured, please get in touch."
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You can report information online at herts.police.uk/report, via online web chat at herts.police.uk/contact, or by calling the non-emergency number 101, quoting crime reference 41/49140/23.
Alternatively, contact Crimestoppers anonymously on 0800 555 111 or online at crimestoppers-uk.org.
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