Israeli air strikes on Gaza may have halted, and a prisoner exchange between Israel and Hamas is ongoing, but tucked behind the headlines, tensions are brewing in Gaza between Hamas and armed groups.

On Sunday, clashes erupted between an armed clan and Hamas security forces, killing at least 27 people, including eight members of Hamas, according to the Ministry of Interior in Gaza.

Caught in the crossfire was 28-year-old Palestinian journalist Saleh Aljafarawi, who was covering clashes in Gaza City’s Sabra neighbourhood between what security sources told Al Jazeera Arabic was an “armed militia” and Hamas.

Is that the only militia in Gaza? Who are these armed gangs? What are their goals? And are they really affiliated with Israel?

Here’s all you need to know:

Who fought Hamas on Sunday?

Media reports and sources said the clan that was fighting Hamas in Gaza City is the Doghmush clan.

The large family has members in various factions across the political spectrum in Gaza.

Momtaz Doghmush was involved in the group Jaish al-Islam’s capture of Israeli soldier Gilad Shalit in 2008. Other clan members have been in Hamas or groups affiliated with the Palestinian Authority.

Some reports claimed the Doghmush who fought Hamas on Sunday were affiliated with Israel, but other sources from Gaza deny the affiliation with Israel.

What happened?

The Sahem unit, an armed unit affiliated with the Interior Ministry, said the clashes started on Saturday when “an outlaw gang killed resistance fighters from the Qassam Brigades”, the armed wing of Hamas, near the Jordan Field Hospital in Gaza City.

Witnesses told the BBC that 300 Hamas fighters stormed a residential block where Doghmush gunmen were holed up, and a Palestinian security source told the Reuters news agency that Hamas launched a campaign in Gaza City that killed 32 members of “a gang”.

According to the Interior Ministry, eight Hamas members and 19 clan members were killed. Aljafarawi was also killed.

There was an outpouring of grief over Aljafarawi’s killing in the midst of which a video of him greeting his friend and colleague Anas al-Sharif circulated on social media.

Al-Sharif, an Al Jazeera correspondent, was killed by Israel on August 10. Aljafarawi, like al-Sharif, was reportedly threatened multiple times by the Israelis over his reporting.

Are the Doghmush really backed by Israel?

That’s still unclear.

There is conflicting information. Some reports from inside Gaza said the clan has an Israeli affiliation, but the group’s leaders have denied that.

In early October, Nizar Doghmush, head of the clan in Gaza City, told the Los Angeles Times he had been contacted by the Israeli military to manage a so-called humanitarian zone in Gaza City.

He told the newspaper he refused and added that the Israeli military then bombed his neighbourhood in Gaza City, invaded and systematically destroyed houses.

The Doghmush and Hamas have an animosity towards each other, which in the past has devolved into armed clashes.

But Israel does have a history of funding and supporting groups in an effort to foment internal tensions.

Israel does support militias in Gaza, right?

Yes.

Israel is widely recognised to be behind the Popular Forces, a militia led by Yasser Abu Shabab of Gaza’s Tarabin Bedouin tribe.

The Tarabin, however, have denounced Abu Shabab.

While Israel claimed Hamas was stealing aid from the people of Gaza, it was revealed that the Popular Forces was the one looting aid to resell to Gaza’s starving people. Hamas reportedly clashed with the Popular Forces on a few occasions since September 2024, accusing them of being Israeli collaborators.

Israel has also reportedly backed a group calling itself the Strike Force Against Terror, led by Hussam al-Astal, a member of the al-Majida clan. Al-Astal’s group also clashed with Hamas in early October before the ceasefire was announced, according to Israeli media.

Al-Astal is a former officer in the Palestinian Authority’s (PA’s) security forces but was accused by the PA and Hamas of collaborating with Israel in the 1990s. Israeli media reports said al-Astal was a member of Abu Shabab’s militia and continues to coordinate with the Popular Forces leader.

He reportedly controls a village called Qizan an-Najjar in the Khan Younis governorate in southern Gaza.

The ongoing activity of these groups against Hamas and against civilians has contributed to a sense of unrest, as several people in Gaza have told Al Jazeera.

What happens now?

The fighting has stopped, but further clashes could still erupt in a society devastated by two years of Israel’s genocidal war.

The security void could lead to confrontations between groups looking to gain influence or territory.

For its part, Hamas has denied deploying fighters to the streets.

Meanwhile, Palestinians are returning to what is left of their homes in northern Gaza, and desperately needed humanitarian aid has started to enter the Gaza Strip.

Israel has killed at least 67,806 people in Gaza since the war began in October 2023.