THE number of detainees taking part in a hunger strike at the US-run Guantanamo military prison has grown to 77 - an increase of 25 in just the past few days, a spokesman says.

Lieutenant Colonel Samuel House said in a statement that of the detainees refusing food, 17 are receiving "enteral feedings," or being force-fed via tubes.

Five of the inmates have been hospitalised, although none faces "life-threatening conditions," House said.

The facility, which houses 166 detainees, has been hit by hunger strikes since February 6, when inmates claimed prison officials searched their Korans for contraband.

Officials have denied any mishandling of Islam's holy book.

The hunger strikers are protesting their incarceration without charge or trial at Guantanamo for the past 11 years.

Lawyers representing inmates at the prison have said most of the estimated 130 detainees at Guantanamo's Camp Six wing, which houses "low-value" prisoners, are on hunger strike.