The Hamas terror group on Tuesday gave Israel 24 hours to accede to the demands issued by hunger-striking Palestinian prisoners, warning that otherwise it would increase its own demands in a future prisoner exchange with the Jewish state.

For each day the standoff between Israel and the Palestinian inmates held in Israeli jails continues, the terror group said it will add the names of 30 prisoners to the list of detainees it wants released in a future swap deal.

The deadline was set by the military wing of Hamas, the de facto rulers of the Gaza Strip after the organization seized control of the coastal enclave in 2007.

“We warn the enemy not to ignore the just and legitimate demands of the prisoners, and we say we are giving the enemy leadership 24 hours to respond,” a spokesman for the Izz ad-Din al-Qassam Brigades said in a recorded speech.

Otherwise, he warned, Israel would “pay the price every day they delay responding to the demands.”

Palestinian officials say some 1,500 prisoners participated in the hunger strike that began on April 17, with detainees ingesting only water and salt in protest of their conditions. Israel Prison Service spokesman Assaf Librati said on Monday that 870 prisoners are still refusing to eat. Israeli officials have said they will not negotiate with the prisoners.

A Palestinian demonstrator holds a flag bearing an image of Marwan Barghouti during a protest in support of Palestinian prisoners on hunger strike in Israeli jails, near the West Bank settlement of Beit El, north of Ramallah on April 23, 2017. (AFP PHOTO / ABBAS MOMANI)

A Palestinian demonstrator holds a flag bearing an image of Marwan Barghouti during a protest in support of Palestinian prisoners on hunger strike in Israeli jails, near the West Bank settlement of Beit El, north of Ramallah on April 23, 2017. (AFP PHOTO / ABBAS MOMANI)

Israel is seeking the release of three Israeli men who crossed into the coastal territory of their own accord: Avraham Mengistu and Hisham al-Sayed, as well as Juma Ibrahim Abu Ghanima, whose presence in Gaza is unconfirmed. Hamas, an Islamist terror group that seeks to destroy Israel, also holds the bodies of IDF soldiers Oron Shaul and Hadar Goldin, who the army determined were killed in action in the 2014 Gaza war.

In the past, Israel has released thousands of Palestinian prisoners in return for captured Israeli soldiers, civilians, or the remains of Israeli soldiers.

IDF soldiers Oron Shaul (left) and Hadar Goldin (right) (Flash90)

IDF soldiers Oron Shaul (left) and Hadar Goldin (right) (Flash90)

As a precondition for negotiations, Hamas demands that Israel release all Palestinian prisoners freed in the 2011 exchange for captured Israeli soldier Gilad Shalit and rearrested in 2014 when three Israeli teens were abducted and killed in the West Bank. Despite occasional media reports of negotiations, via a mediator between Israel and Hamas, no deal has yet been formulated.

In 2011, as part of the prisoner exchange deal for Shalit, an IDF soldier who had been kidnapped and held by Hamas in Gaza, Israel released 1,027 Palestinian and Israeli Arab prisoners.

Over the past three weeks, support for the hunger strike has gained momentum with West Bank marches, strikes, and backing on Palestinian social media.

The hunger-strikers, led by convicted terrorist and popular Palestinian figure Marwan Barghouti, who is serving five life terms for his role in deadly attacks, have become a cause celebre, with near daily demonstrations in support of them.

Some 6,500 Palestinians are currently detained by Israel for a range of terror offenses and crimes. Around 500 are being held under Israel’s system of administrative detention, which allows for imprisonment without charge.

Palestinian prisoners have mounted repeated hunger strikes, but rarely on such a scale.

Among the demands made by Barghouti and fellow prisoners are the resumption of a second monthly visit by family members (a benefit that was canceled by the International Committee of the Red Cross last year due to budget cuts), the prevention of family meetings being canceled for security reasons, extending the length of each visit from 45 minutes to an hour and a half, and the restoration of academic studies and matriculation exams for prisoners. Other demands include more television channels being available in cells and the installation of public telephones in security wings.

Barghouti is popular among Palestinians, with polls suggesting he could win the Palestinian presidency. Many Israeli and Palestinian analysts have speculated that Barghouti organized the strike in a bid to boost his declining power in Palestinian politics.