A protest has been held outside Cardiff prison to try and persuade the Home Office to re-house nine asylum seekers who have been held for the past three weeks.
The protesters gathered outside the prison on Wednesday evening
The nine men were transferred there from a detention centre near Heathrow.
Politicians are angry the men are being held in jail as they are not criminals.
The Home Office said they could not comment on individual cases, but said the situation was "temporary".
The asylum seekers include three men from Jamaica and another from the Darfur region of the Sudan.
They were transferred from the Harmondsworth Immigration and Removal Centre, near Heathrow, following disturbances there last month after a detainee committed suicide.
Another asylum seeker from Harmondsworth is being held at Parc Prison, Bridgend.
Plaid Cymru's social justice spokesperson Leanne Wood AM, who has written to the minister urging the asylum seekers' immediate release, was among around 200 protesters outside the jail.
She said: "We want to send a clear message to the Home Office that housing asylum seekers in prison is not acceptable as they're not criminals.
"We want to give our support to the people in the prison and hopefully if we can make enough noise they'll hear us."
Welsh Social Justice Minister Edwina Hart has said she was "very concerned" after visiting the men earlier this week.
Mrs Hart said "no-one should be treated in a worse way simply because they are an asylum seeker".
She said she would be writing to ministers in the UK about the assembly government's concerns urging the "swiftest possible resolution" to the issue.
The 481 Harmondsworth detainees have been dispersed to prisons and other detention centres across the country - with some being held in police custody, the Home Office said.
A spokesman for the Home Office said that he could not comment on individual cases but said that work was being done to reopen Harmondsworth as soon as possible.
He said that none of the detainees were being held with convicted prisoners and that it was a "temporary situation due to the closure of Harmondsworth".
Reverend Aled Edwards, a member of the Cardiff Asylum Network and chairman of the charity, Displaced People in Action, has had several meetings with the asylum seekers to help them
All of the detainees were removed from Harmondsworth
He said there were six bona fide asylum seekers held in the jail while the other men were waiting to be deported.
"When I went to see them, they were very angry because they felt that the whole world had forgotten about them for three weeks," said Rev Edwards.
"I think there are concerns. It has to be quite wrong to lock people up for 23 hours a day for claiming asylum."