Relatives of Yemeni detainees at Guantanamo and activists demonstrated on Tuesday outside the US embassy in Sanaa demanding the release of inmates on hunger strike.
"Obama, Obama, enough detentions," the protesters chanted in an appeal to US President Barack Obama, an AFP correspondent reported.
Twenty protesters wore orange jumpsuits, similar to those worn by prisoners at the US detention centre in Guantanamo Bay, Cuba.
"We urge the US government to immediately release the detainees at Guantanamo," read a banner carried by protesters at the rally.
The "94 Yemeni detainees are on hunger strike in Guantanamo," said Mohammed al-Ahmadi, an official from Al-Karama, a local non-governmental organisation.
A veiled black-clad mother of a detainee also said inmates were on hunger strike.
"The Americans say they hold our sons to rehabilitate them. They can return them to us and we could take care of them," said the woman who told AFP her son was captured in Pakistan where he worked.
"He has no links to terrorism," she said.
The protesters handed a US embassy representative a petition urging the release of Guantanamo prisoners.
Attorneys representing inmates at the prison have said most of the estimated 130 detainees at Guantanamo's Camp Six wing, which houses "low-value" prisoners, were on hunger strike.
US authorities, however, put the number of hunger strikers at about three dozen.
An inmate detained at Guantanamo for more than a decade without charge gave a graphic account on Monday of his participation in a two-month-old hunger strike at the US-run military prison.
In an op-ed published in the New York Times entitled "Gitmo Is Killing Me," Samir Naji al-Hasan Moqbel said he had lost over 30 pounds (13.6 kilos) since going on hunger strike February 10 and that a fellow inmate weighed just 77 pounds.
Moqbel said at least 40 people were taking part in the protest.
Like most of the striking inmates, he has never been charged with a crime or put on trial, and is not viewed as a threat to US national security.
However he cannot be released because of a moratorium on repatriating Yemenis enacted by Obama in 2009 after a plot to blow up an airliner on Christmas Day was traced back to Al-Qaeda's Yemeni franchise.