Eight released Israeli hostages wrote a letter to the International Committee of the Red Cross on Monday, asking the humanitarian organization to provide medical assistance and to visit their relatives still being held by Hamas in Gaza.

In an October 7 cross-border attack, Hamas militants killed 1,200 people and seized 240 hostages, according to Israeli tallies. Hamas freed over 100 of the captives during a seven-day truce last month in return for the release by Israel of scores of Palestinian detainees, as well as an increase in humanitarian aid shipments to Gaza.

While the deal was brokered by Qatar, the US, and Egypt, the handover of hostages and Palestinian detainees was facilitated by the Red Cross.

Israeli authorities have said seven civilians and an army colonel died in captivity and that 137 hostages remain in Gaza, their condition not always known.

The released hostages said in their letter that they had endured "harsh conditions" while being held and asked the Red Cross to help secure the immediate release of those still in captivity. They also asked the Red Cross to make visits to verify the health status of the captives and provide medical assistance and proof of life which they said was urgent.

The Red Cross has not commented on the letter, but it has previously called for agreements to allow its teams to check on hostages and deliver medication. It has said it cannot force its way to where hostages are held and do not always know their locations.

The hostages said their Hamas captors subjected them to "lack of medical treatment for illnesses and injuries with culpable neglect, severe food shortage and unsanitary living conditions".

"Some of the hostages undergo psychological and physical abuse," the letter said.

The letter also requested a meeting with the organisation's President.

Reuters