The U.S. military says just over half of the prisoners at Guantanamo Bay are on a hunger strike.

A military spokesman says 84 prisoners have been classified as hunger strikers at the U.S. military base in Cuba. The prison's population is 166.

Army Lt. Col. Samuel House says 16 of the 84 prisoners are being force-fed and five have been hospitalized. He says none of the hospitalized men have life-threatening conditions.

About a week after a clash between guards and prisoners, the hunger strike is steadily growing. On Tuesday, the number of hunger strikers was 45. By Friday, 63 prisoners had joined.

Prisoners have been on a hunger strike since early February to protest conditions and their indefinite confinement. The U.S. holds 166 men at the prison, most without charge.