A demonstration will take place outside the US naval base in Cuba on Thursday to mark the fifth anniversary.
Michael Ratner, the president of the Centre for Constitutional Rights, said: "The abomination that is Guantanamo Bay must be shut down.
About 395 men are currently held there, detained because of their alleged links to al-Qaeda or the Taliban.
The government has blocked their access to US courts, claiming it has the authority to detain them indefinitely to keep they country safe.
|Detainees relatives and former prisoners will |
take part in a protest in Cuba [AFP]
Former detainees and the families of men still being held in the military prison will march to the security perimeter surrounding the US enclave in Cuba.
Zohra Zewawi, whose son Omar Deghayes has been held at the prison camp since his arrest in Pakistan in 2002, Asif Iqbal, a former detainee, and several American peace activists will demand the closure of the facility.
"I came here to ask to shut down Guantanamo and release everybody who is there, and ask George Bush ... who is a father how he would feel to have one of his daughters detained in such a place," Zewawi said on Tuesday.
Iqbal was 20-years old when he travelled to Pakistan to get married and said he went to Afghanistan out of curiosity and a desire to help the Afghan people when the US invasion began.
He was arrested in Mazar-i-Sharif in November 2001, flown to Guantanamo and subjected to endless interrogations, sensory deprivation, exposure to extreme temperatures and spent days on end in shackles, he said.
After three months in solitary confinement, Iqbal signed a confession that he had been at an al-Qaeda rally in Afghanistan in 2000. British police later corroborated Iqbal's account that he had been in Britain at the time.
"The burden of Guantanamo is still there. Until the prison is closed down I cannot get on with my life," he said.
Only 10 detainees have been charged by the military tribunal set up to try the inmates.