The two victims, a 22-year-old man and a 28-year-old women were assaulted by three men in St Paul’s Road, Southsea, in the early hours of Saturday morning.
The incident has shocked the local LGBT+ community, and transgender campaigner Katie Yeomans said people need to be more confident in reporting homophobic crimes against them.
She said: ‘As a transgender person I think it is absolutely disgusting that people are carrying out verbal and physical attacks on people purely because of their gender and sexuality.
‘I would encourage anyone who suffers abuse to report it to the police.
‘Generally speaking a lot of people won’t report it out of fear of people coming back and saying they grassed to the police.
‘A lot of people are not comfortable with their sexuality and gender, and they are often embarrassed.’
The Southsea resident, who has identified as transgender for two years, added that she had not received much abuse herself.
But she has been involved in publicity campaigns - including speaking in schools - to teach people that homophobia is not acceptable.
Councillor Lee Hunt, who represents the Central Southsea ward on Portsmouth City Council, is in a civil partnership and said he was shocked at what had happened.
He added that the attack may have been linked to the result of the European Union referendum in June, where voters opted to leave the institution.
The Liberal Democrat councillor said: ‘I would have hoped that this was all in the past. After the Brexit vote there has been this atmosphere of aggression.
‘Since then all these extremist people think they have this right to go out and attack anybody who is seen as different.
‘Personally I have suffered a great deal both in the establishment and in the street.’
He said that in general people in Portsmouth were “very liberal and tolerant” towards members of the LGBT+ community.
But he added: ‘We need more police on the streets and if people see abuse going on they should report it.’
Hampshire Police said the woman involved in the incident suffered a fracture around her left eye socket, while the man received a cut lip.
A spokesman added that no arrests have been made.
Anyone who saw what happened should call 101.