A hunger strike among prisoners at Guantanamo Bay keeps growing.

Lt. Col. Samuel House said Saturday that 100 of 166 prisoners at the U.S. base in Cuba have now joined the strike.

He says 19 are receiving liquid nutrients through a nasal tube to prevent dangerous weight loss. House says five of those are at a hospital under observation but that they do not have any life-threatening conditions.

Lawyers for the detainees say the military is undercounting the number of hunger strikers.

Prisoners began the hunger strike in February to protest conditions and indefinite confinement.