A US military spokesman said the number of prisoners on hunger strike at Guantanamo Bay has been raised to 92 based on evaluations by medical personnel at the American base in Cuba.
The new figure is up by eight prisoners from a day earlier and represents more than half of the 166 men held there.
16 of the hunger strikers are on feeding tubes, five of whom are hospitalized, Lieutenant Colonel Samuel House said in a statement issued earlier this week.
House said the military arrived at the new figure Wednesday because doctors have been able to evaluate the prisoners more closely after moving them to single cells out of a communal area.
The move sparked a brief clash between guards and prisoners on April 13.
On Friday, 63 inmates were refusing to eat, and Tuesday of last week just 45 were taking part.
The detention facility at Guantanamo was opened in 2002 to house prisoners rounded up in the "War on Terror" waged by President George W. Bush’s administration following the 9/11 attacks. 
In January 2009, Obama signed an executive order to close down the facility, but has failed to follow through with a promise he made during his first electoral campaign.
Lawyers for the men, who are mostly held without charge, have called on the Obama administration to act on its promise to close the camp.
They said the participants' health had deteriorated alarmingly, and that some had lost between 9 and 14 kilograms. The military was allegedly minimizing the number of men refusing to eat in protest of their confinement.