A hunger strike among detainees at Guantánamo Bay, Cuba, who have been imprisoned by the United States military without trial — some for more than a decade — is continuing to grow, although there is sharp disagreement between the military and lawyers for the detainees about how many are participating.

As of Monday morning, 28 of the 166 prisoners had refused enough continuous meals to be deemed hunger strikers in the official count, and 10 of them were being force fed, said a military spokesman, Capt. Robert Durand. That was up from 26 hunger strikers and 8 who were being force fed on Friday, according to the military’s count. Three detainees have been hospitalized for dehydration, Captain Durand added.

Lawyers for detainees, however, citing declassified notes of conversations with their clients in person and by phone, claim that the military’s numbers are significantly undercounting the actual level of participation. Their clients have told them that an overwhelming majority of the detainees in Camps Five and Six — where low-level suspects who are not facing any charges before a military commission, the bulk of the inmate population, are being held — have been refusing to eat for weeks, they said.

Ramzi Kassem, a law professor at the City University of New York and a lawyer for several Guantánamo prisoners, said he spoke by telephone on Friday with two clients who are participating — Moath Hamza Ahmed al-Alwi, a Yemeni held in Camp Six, where detainees who comply with rules live in communal housing, and Abd al-Hadi Omar Mahmoud Faraj, a Syrian held in Camp Five, where noncompliant detainees live in individual cells.