A WOMAN has described how she 'froze in fear' after a pervert exposed his genitals and began pleasuring himself on the bus.

The shocked passenger has taken to Facebook to publicly warn other women and girls about the man, who has not yet been caught by police.

She said she boarded the Abingdon-bound X3 bus at St Aldates in Oxford, at about 7.30pm last Wednesday.

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In her post, she said the bus was 'packed' so she sat right at the back of the bus at the top deck, and other people were in the immediate vicinity.

A man came to sit in the same row and she thought little more of it, until the bus arrived in Abingdon.

She wrote: "I've noticed some weird arm movements but [did] not look up at him, until the noises started...I could feel him looking at me.

"Baring in mind I get mistaken for a minor, A CHILD, on many occasions, this 'man' was sat next to me staring at me and making weird noises while masturbating with his genitals fully on show."

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She said she was 'terrified' and 'literally froze in fear' but then grabbed her bag and fled to the lower deck.

The post added: "I sat having a panic attack before building up the courage to go and tell the bus driver."

She said the driver went to confront the man but he was no longer there, having apparently got off at another stop in the town.

The woman immediately went to the police station to report what had happened, and said she was due to be interviewed yesterday.

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She added: "This guy is clearly a predator - please be aware he’s still out there.

"Everyone, especially girls, if you’re travelling alone on the bus between Oxford and Abingdon, it doesn’t matter what time it is, do not sit at the back of the bus because I really really don’t want anyone to experience the actual terror I felt in that moment."

She said she gets the bus regularly but felt 'trapped' in that moment, adding: "Please be careful out there, he hasn’t been caught so he could do this to someone else."

The man was described as Asian, in his 30s, who was wearing dark jeans, a white top and a black jacket.

Thames Valley Police has been contacted for further information. 

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The woman said the bus driver was 'great', adding: "She stopped the bus and got off, rang the depot to report it and gave me the bus number, and told me there was CCTV and took down my details."

Oxford Bus Company, which runs the X3, is supporting police with their investigation and has provided CCTV footage from the service. 

A spokesman said: "Passenger safety is paramount to us and allegations of this nature are extremely rare on our bus network, which carries thousands of passengers safely daily."

More than 500 people have shared the woman's post since it went public on Thursday.

Commenters described the man's behaviour as 'disgusting' and 'sickening'.

One person responded: "Absolutely disgraceful behaviour. It must have been extremely distressing for you to experience this, but very brave of you to share."