GAZA CITY, Gaza—More than a month after The Daily Beast reported evidence suggesting Israeli soldiers carried out the summary execution of six men amid fierce combat in late July, there are no signs that the Israeli government is investigating the matter. It has declined to respond to repeated inquiries. The independent organizations Human Rights Watch and Amnesty International, which the Israeli authorities have barred from Gaza, are unable to follow up in detail. And a United Nations investigation of abuses on both sides is barely under way.

The Daily Beast has continued its own investigation, however. And the picture that’s emerging tends to confirm the story of a summary execution, on the one hand, while undermining subsequent reports by some in the international press who suggest the dead men, left to rot in the bathroom of a battered house, were merely innocent bystanders. Instead, they appear to have been hardened guerrilla fighters from Islamic Jihad who were trying to ambush Israeli soldiers when they themselves were caught, captured, herded into an abandoned bathroom and gunned down in an incident that, if confirmed, would be a war crime.

After repeated efforts, I was finally able to make contact with a member of Islamic Jihad who said he fought in the battle of Khuzaa and who presented a detailed picture of what happened from his organization’s perspective.

As we sipped Arabic coffee in a Gaza City hotel, the well-coiffed and slightly awkward man in his late twenties, who chose to call himself Abu Muhammad, talked about 23 ferocious days of combat, and about the last radio communication he heard with the six fighters before they were captured and killed.

From July 16 to August 8, Abu Muhammad said, he and the others were hidden below Khuzaa in a series of tunnels that he says are connected to other underground passages linking Gaza from north to south. He maintains that Israel, which made these a prime target, only managed to destroy a fraction of them during the war.

Abu Muhammad, occasionally staring off into the distance and clearly shaken, said he and the others had arrived in Khuzaa, which is right on the Gaza-Israel border, by tunnel days before Israel began its ground assault.

In the beginning, fighters from Islamic Jihad joined with the Al Qassam Brigades of Hamas and the Popular Resistance Committees in a furious tit-for-tat mortar and rocket exchange with Israeli forces lining the border.

However, as the ground invasion neared, according to Abu Muhammad, an intense Israeli campaign that included bombing from F-16s and intense artillery fire killed many fighters. Civilians began fleeing as shelling intensified, but real panic came when Israel moved in its tanks, and the civilian exodus began in earnest.

During this phase of the fighting, the Palestinian resistance in the town hunkered down and waited as the Israeli shelling and aerial bombardment laid waste to one building after another in order to clear a path for tanks and jeeps. From the tunnels, the fighters could hear above them Israeli troops carving out the buffer zone that would eat up about 44 percent of Gaza’s territory and leave much of that area reduced to rubble.

“After we had been in the tunnels about a week, with the Israelis firing mortars, they drove in with the tanks,” said Abu Muhammad, who apologized about his uncertain grasp on specific dates. He’d lost track of the days after so much time underground, he said, but he remembered, “There were around 60 tanks.”

Only when Israel had positioned its forces around Khuzaa did the armed Palestinian groups begin their counterattack, according to Abu Muhammad. “First we targeted the tanks and the jeeps with IEDs,” he said mechanically, as if recalling a combat briefing. In the second stage of their effort to bog down and then repel Israeli forces, the three guerrilla factions launched a multi-pronged hit-and-run campaign from all directions.

“Some of our people would come out of the ground, attack the soldiers and then disappear back into a tunnel,” said the combat veteran. “Others surprised them from empty houses,” he said.

In one of those brazen attacks, says Abu Muhammad, fighters used a shoulder-fired rocket to hit a house the Israeli army had taken over, killing two of the soldiers with sniper fire as they fled the building. He is unable to give an overall estimate of Israeli or Islamic Jihad casualties in Khuzaa, but says 130 fighters from his group were killed during the war. (Israeli intelligence puts that number at 182.)

When I visited Khuzaa on four occasions during and after the war, there were clear signs of an intense battle in the ruins of the town. Incoming and outgoing machine-gun fire covered homes and apartments near positions taken by Israeli soldiers. Israeli bullet casings littered the floors of the entrances to residences that were transformed into stucco barracks.

It is amid this type of all-encompassing urban warfare that Abu Muhammad appears to have borne witness to a perplexing, and very possibly criminal, execution of prisoners.

He is unable to pinpoint the date when he says his comrades were mowed down, but he recalls in detail the events leading to their capture and the last moments of their lives, broadcast over Islamic Jihad walkie-talkies.

He stares at the table, speaking softly as he describes how six fighters emerged from the mouth of a tunnel, adjacent to the town’s destroyed mosque and water tower, intending to lead a brief surprise attack on soldiers. Except, in this instance it was the Israeli army that had the element of surprise and the guerrillas found themselves in an all-out firefight at the entrance to the tunnel.

As the Islamic Jihad unit retreated towards the house where they would die, they messaged that one of the fighters was injured and that they were running out of ammunition. They barricaded themselves in the unfinished two-story home. Abu Muhammad heard a drawn-out firefight over the radio. He contends that another Islamic Jihad member watched the events from an adjacent house.

“The wounded resistance fighter demanded to be left at the entrance of the house to fight off the army as they came in,” said Abu Muhammad.

When I was in the house, I found a used medical kit with Arabic instructions in the room next door to the bathroom where the fighters were killed.

Abu Muhammad claims that during the firefight that used up the Islamic Jihad unit’s remaining ammunition, he heard Israeli drone rockets fired into the roof of the house. However, this did not square with what I saw. It is one of the few homes in Khuzaa with no signs of shell damage.

“The Israelis first entered the house and began clashing with the injured fighter,” says Abu Muhammad, describing what he could make out from radio communications and what he says he was told by the fighter who watched from nearby. My request to speak to that fighter was denied by Islamic Jihad for “security reasons.”

When the Palestinians ran out of ammunition, the army moved in. The Israeli soldiers grabbed the fighter in the entrance, “pulled him outside and shot him in front of the house,” Abu Mohammed says. “Then they went into the house with dogs. In situations like this there is no way for these guys to fight off the dogs. I heard their screaming and begging for mercy on the radio.”

Then the line went dead. Repeating the report from the alleged eyewitness, Abu Muhammad contends that Israeli soldiers removed the fighters’ weapons and ammunition vests from the house. “After that there was a long burst of fire from an M16, and then silence.”

On my first visit to Khuzaa I found two ammunition vests around the corner from the bathroom where six bodies were piled. The decomposing corpses wore the black pants and belts that fighters wear, although some were barefoot. They were being carried out and the stench of their rotting flesh and bloated guts made it hard to examine them closely.

Bullet holes lined the tile wall behind where they lay. Israeli bullet casings filled the entrance to the house, where Abu Muhammad says the injured soldier intended to make a last stand before he ran out of ammo.

Islamic Jihad is still withholding the names of its dead fighters, and while Abu Muhammad says the families have been informed, their identities remain secret for now.

While Israeli authorities have declined to address publicly this particular incident, which could be considered a war crime, an Israeli intelligence briefer did supply some interesting statistics to The Washington Post and a few other media outlets last week.

The Israelis estimate the total number of Islamic Jihad fighters in Gaza to be roughly 5,200, while Hamas numbers about 16,000. (That is among a civilian population of roughly 1.8 million, half of whom are children and teenagers.) The 50-day Gaza War this year, which was sparked by a widespread campaign of Israeli arrest raids in the West Bank that was met with Islamic Jihad and Hamas rockets, and which terminated in an uneasy ceasefire, cost the lives of six Israeli civilians and 64 Israeli soldiers. The Palestinian death count, even by the conservative Israeli estimate, was 2,127. Israeli intelligence claims 341 were from Hamas, 182 from Islamic Jihad and 93 from smaller factions, while 706 unquestionably were civilians, presumably including most or all of the 253 women and 495 children known dead. Israeli intelligence, which The Washington Post notes is anxious to reduce the stunning civilian body count, says the intelligence briefer claimed the status of 805 of the dead remained “unknown.”

The fog of Israel’s 50-Day war in Gaza has only just begun to clear and while there is still much mystery shrouding the battle for Khuzaa, the more the record of those events takes shape, the more grim it appears.