The number of detainees on hunger strike at the US military prison in Guantanamo Bay is said to have fallen by almost two-thirds since last week.
Many prisoners are al-Qaeda or Taleban suspects
Spokeswoman Angela King-Sweigart was quoted by the AP news agency as saying that 45 detainees were currently on hunger strike, down from 131 last week.
Prisoners must miss nine meals in a row for the US military to classify them as being on a hunger strike.
Some 500 men are being held without charge at the controversial facility.
Most of the detainees were picked up in Afghanistan, and are accused of ties to the ousted Taleban regime or Osama Bin Laden's al-Qaeda terror network.
The protest began on 8 August, the latest in a series of hunger strikes since 2002.
No explanation was given for the sharp decrease in the number of hunger strikers over the past week, AP says.
Fifteen of the 45 detainees on hunger strike had been taken to hospital, Ms King-Sweigart said, but could not confirm if any were being tube-fed.
Several detainees have been tube-fed during the hunger strike.
The US military says nearly 250 prisoners have been sent to their home countries from Guantanamo since the prison opened.
As most inmates are held as "unlawful combatants", they are not protected by the Geneva Convention and can be held indefinitely, the US government says.