"We will uproot the state of the Jews (Israel) and you and Fatah, and all of the secularists are nothing and you will be overrun by our creeping multitudes," said a masked Islamic State member, Reuters reported.

"The rule of Sharia (Islamic law) will be implemented in Gaza, in spite of you. We swear that what is happening in the Levant today, and in particular the Yarmouk camp, will happen in Gaza," he said.

ISIS fighters overran much of the Yarmouk Palestinian refugee camp in April in Damascus, establishing a foothold in the Syrian capital for the first time. Palestinian and Syrian officials have vowed to retake Yarmouk, a built-up area that housed 160,000 Palestinians and Syrians before the civil war.

"Because of pressures by the Palestinian factions on Daesh fighters, they were forced to retreat from some posts," Abdul-Majid said in April, using a derogatory Arabic acronym to refer to ISIS, according to AP.

Hamas, like ISIS, has a deep animosity toward the state of Israel. But unlike the jihadist group, Hamas does not wish to create an Islamic caliphate in the Middle East. Rather, it wants to defend Palestinian interests.

The Palestinian militant group has been accused of having links with ISIS, despite their recent struggles against the jihadist organization that has conquered large areas of Syria and Iraq since the summer of 2014.

Hamas has been accused by Israeli Intelligence Minister Israel Katz of partnering with affiliates of ISIS in Egypt’s Sinai peninsula, a charge that has been long denied by the Palestinian group.

"There is cooperation between them in the realm of weapons smuggling and terrorist attacks. The Egyptians know this, and the Saudis," Katz told a Tel Aviv conference organized by the Israel Defense journal, Reuters reported.

However, other analysts believe that the challenge posed by ISIS could actually bring Israel and Hamas closer together as they look to try a fight a common enemy. Experts have raised the prospects of a five-year ceasefire deal, which would allow Hamas to open a seaport in the Gaza Strip and end a naval blockade imposed by Israel.

"It is not the first time that Hamas is sending the message that it would like to discuss a Hudna (long-term truce) with Israel," said Haim Tomer, former head of overseas operations at Israel's Mossad intelligence agency, told Reuters.

"(Hamas) is a movement that has become a regime and when you are a regime you can suffer as a result of your grip on power. This is what they are now learning. So they are looking for options," he said.

A Hamas spokesman, Sami Abu Zuhri, said the group had received "ideas" but no concrete proposal, regarding the possible ceasefire.

"We will deal with any effort that would lead to breaking the blockade and alleviate the suffering of Gaza people on condition it does not affect our national cause."

Three separate rocket attacks launched from the Gaza Strip into Israel in June were the work of the Salafist group, the Omar Brigades, which has pledged its loyalty to ISIS. Hamas denied taking any part in these strikes.

Israel responded with airstrikes, but they deliberately targeted buildings and facilities that Hamas no longer used, so as to not inflame the situation.