No room for IS

At a training base tucked away in an industrial area of Gaza City, one of the military leaders of the al-Nasser Salah al-Din Brigades dismissed claims that the "Islamic State" militant organization (also known as ISIS or ISIL) is active in the enclave.

Abu Sayyaf, a leader of the Islamist group, wore a black mask on his face while a dozen of his troops practiced military drills behind him. As Israeli drones and monitoring balloons buzzed overhead, he vowed that Palestinian armed groups would never allow a local branch of IS to take root and grow in Gaza.

"We are not scared of Da'esh [IS] because Gaza would never accept its presence," he said. "Internally, the armed factions would never permit it. We would step in."

Although Hamas has controlled Gaza since 2007, several armed groups from across the political spectrum - Islamists, secular nationalists, leftists - operate in the region, particularly during times of war with Israel, such as the brutal 51-day faceoff between Israel and Gaza last summer.

Kidnappings, threats

Since the war concluded, several reports of IS have sprung up in the media. In early February, a group claiming to be affiliated with IS apparently kidnapped and assaulted Palestinian journalist Mohammed Omer and two others in Gaza City. They were later released.

Just two weeks earlier, Salafist activists assembled outside the French Cultural Center in Gaza to protest in support of IS and the deadly Charlie Hebdo attacks in Paris earlier that month.

In December a pair of leaflets supposedly issued by local IS affiliates in Gaza started popping up. One of the leaflets threatened women who do not dress in a way the group deems acceptable.

The other leaflet threatened 18 local writers and poets for supposed "atheism." "We warn the writers and poets of their wanton sayings and atheist deeds," it read. "We give the apostates three days to retract their apostasy and wantonness and enter the religion of Islam anew."

A video posted on YouTube earlier that year showed a group of masked militiamen in Gaza declaring their allegiance to IS.

Back in February 2014, the Mujahadeen Shura Council in the Environs of Jerusalem, a Gaza-based Salafist group, released a statement declaring that it is "committed to helping [IS] and bolstering its ranks."

'Not a religious war'

"We are not fighting a religious war here in Gaza," Abu Sayyaf said, predicting that IS-affiliated groups will not gain much popularity among Gazans. "It's a war to liberate occupied land."

Others choose not to directly address the possibility of IS's growth in Gaza. Abu Khaled, a commander in the National Resistance Brigades, the armed wing of the leftist Democratic Front for the Liberation of Palestine, claims that IS is supported by the US.

"The Palestinian resistance does not interfere in other Arab affairs," Abu Khaled said. "But Palestine is not a fertile ground for groups like IS. The resistance is united on the ground. Our enemy is the Israeli occupation; not each other," he said.

Since Hamas took over Gaza in 2007, it has clamped down on other armed groups and limited their ability to act independently, says Benedetta Berti, a security analyst at the Tel Aviv-based Institute for National Security Studies.

Although Salafist groups have "been quite restrained in Gaza," rapid gains made by IS and similar groups in the Middle East nonetheless have "led, to some extent, to the rejuvenation of some of the pre-existing small Salafi-jihadist cells [in Gaza]", Berti remarked.

IS and likeminded groups reject Hamas's nationalism, while Hamas is committed to armed struggle against Israel.

'Branches of the same poisonous tree'

Tensions between Hamas and hardline Salafist groups boiled over as far back as 2009, when Gaza security forces fought the Salafist Jund Ansar Allah in the southern strip. Following the group's declaration of an Islamic emirate in Gaza, Hamas security forces killed spiritual leader Abdel Latif Moussa and dozens of his gunmen in an overnight gun battle.

Israeli Prime Minister Benjamin Netanyahu has tried to promote the idea that there are few relevant differences between Hamas and IS. "ISIS and Hamas are branches of the same poisonous tree," he declared while addressing the United Nations last September. "When it comes to their ultimate goals, Hamas is ISIS and ISIS is Hamas."

Joshua Landis, director of the Center for Middle East Studies at Oklahoma University, explained that Netanyahu "wants to paint his Palestinian enemy as America's enemy, equating the two" at a time when US-Israel relations are troubled.

"We would like to reassure everyone that IS does not exist in the Gaza Strip, and the security agencies are in full control of the situation," Eyad al-Bozum, spokesperson for Gaza's interior ministry, told the Arabic-language news channel Al-Mayadeen back in December.

Although IS-affiliated groups are present, Berti says it is impossible to estimate the exact number of fighters or supporters. "Militarily, none of these small groups or cells can challenge Hamas," she concluded. "Overall the balance of power in terms of weapons and manpower is still in Hamas' favor."