Some 100 Palestinians have been rejecting food for more than two weeks after Israel failed to implement previous agreements regarding their detention.
Israeli prison authorities refuse to remove devices that jam phone reception in certain wings to prevent Palestinians from communicating with the outside world.
Israel had agreed to remove the devices following a previous hunger strike.
Palestinians are also demanding that Israel fulfill its promise to install public telephones in prisons so that detainees can talk to their families.
The 42-year-old father of two is from the Palestinian village of Dura near the occupied West Bank city of Hebron. He is a leukemia survivor.
Ghannam was transferred to medical care following severe deterioration in his health.
Ismail Ali, 30, from the occupied West Bank village of Abu Dis, has been refusing food for more than 60 days as well.
Tariq Qaadan, 46, from the occupied West Bank city of Jenin, has been on hunger strike for more than 55 days.
Qaadan has spent 11 years in Israeli prisons, many under administrative detention.
Palestinian prisoner Sultan Khallouf, 38, from the northern West Bank village of Burqin, near Jenin, suspended his hunger strike last week after 67 days without food.
Israeli prison authorities agreed to release Khallouf on 15 December. He was protesting his administrative detention, and has previously spent some four years in Israeli prisons.
Israel typically issues administrative detention orders for six-month periods, but can renew them indefinitely.
Under such orders, occupation forces hold individuals without charge or trial and detainees are not allowed to see supposed evidence against them.
This Israeli practice is a direct continuation of British colonial rule and may constitute a war crime.
Israel is currently holding 460 Palestinians in administrative detention.
Palestinians in the occupied West Bank and Gaza Strip held demonstrations of solidarity with the prisoners.
Palestinians protested near the Red Cross headquarters in the town of al-Bireh in the occupied West Bank:Palestinians also demonstrated near the Erez checkpoint in the northern Gaza Strip:
Raid on prisoners rights group
Soldiers took laptops, books, memory cards, documents and other equipment.
Israel conducted similar raids on Addameer in 2002 and 2012. Israel also regularly imprisons the group’s staff members.
Israel issued Nasser, 48, with an administrative detention order shortly after his arrest, and renewed it again last week.
This means he will spend at least four more months behind bars without charge or trial.
Addameer said such incursions “will not stand in the face of any duties the organization has for Palestinian political prisoners.”
Israeli forces also forced entry to the offices of the General Union of Service Sector Workers during the same raid.
And on Tuesday, Israeli forces raided the offices of the Union of Palestinian Women’s Committees in the occupied West Bank city of Hebron.
Pictures of the damage caused by Israeli forces circulated on social media:
Solidarity with Addameer
Adalah, a group that advocates for the rights of Palestinians in Israel, condemned the raid on Addameer as a “new step in Israel’s policy of restricting Palestinian human rights institutions.”
The incursion was part of Israel’s “efforts to defame and incite against human rights defenders,” Adalah added.
Amnesty International called the attack an “assault on civil society.”
“The chilling raid by Israeli forces against Addameer demonstrates the Israeli authorities’ clear determination to crush peaceful activism,” Saleh Higazi, deputy director of Amnesty’s Middle East program, stated.
“This was a sinister and calculated attack designed to curtail Addameer’s vital human rights work.”
Palestinian human rights group Al-Haq said that “private property of human rights organizations in occupied territory” is protected under international law.