A family sleeps outside their destroyed house in Jabalia's Ezbet Abed Rabbo district in northern Gaza.

Karl Penhaul
CNN Correspondent

Huge freshly-printed posters were beginning to appear on billboards around Gaza City. The banners depicted masked fighters firing heavy machine guns or red-tipped rockets.

The war had ended just three or four days before. These were signs Gaza's fighting factions were still very much in business and keen to portray their campaign of the last three weeks as a victory against Israel.

CNN's producer in Gaza had been working his contacts. He's well acquainted with Gaza's underbelly.

For several days now he had got word that the fighting factions he was reaching out to were too busy to meet. They were regrouping and retooling just in case the ceasefire didn't hold.

Then after hours of waiting one morning, Abu Rahma got a call. The northern Gaza commander of the Salaheddin Brigades was ready to meet.

We picked our way through Gaza's backstreets, still strewn with rubble.

Young men in civilian clothes stood on street corners on the lookout. Gazans call these spotters "Weierweis" (pronounced "warweers"), after a popular make of walkie-talkie they use to relay messages up the chain of command.

At the city limits, a contact meets us and leads us into an orange grove, like the many that stretch from here up to the Israeli border.

We're told to turn off cell phones and take out the batteries, an attempt to avoid what they fear could be electronic surveillance by the Israeli military. Under the low hanging branches, six militants have taken up positions and camouflaged themselves with foliage.

The Salaheddin Brigades are part-funded by Hamas and fight in close coordination with them. In fact they're the military wing of the Popular Resistance Committees (PRC) – a mix of Islamic factions.

Since they were created in 2000, they've gained a reputation as hardcore fighters. They've frequently launched rockets into Israel. In 2003 they were blamed for ambushing a U.S. diplomatic convoy, killing three security guards and wounding a diplomat. And in June 2006 the Brigades claimed joint responsibility for burrowing under the Gaza-Israeli border and capturing an Israeli army corporal, Gilad Shalit, who is still missing.

With a red and white keffiyeh scarf wrapped around his neck and sporting a close-cut beard I'm introduced to Abu Jamal, the northern Gaza commander for the Salaheddin Brigades. He's clutching an American-made M4 assault rifle.

His comrades are armed with AK-47s, two with rocket-propelled grenades.

This isn't exactly a show of strength. This is a small cell, I counted seven men including the area commander. But they display a certain bravado about their exploits against the Israelis.

The group talks how they fought guerrilla-style against the Israelis using sniper fire and ambushes to try and stall the Israeli advance and on occasion getting in behind Israeli lines to continue firing rockets at southern Israeli towns. They say they survived for three weeks moving quickly and eating little more than a handful of dates and drinking water.

The full facts of the militant campaign are difficult to independently verify. The Israeli Defense Forces say they faced hit-and-run attacks but fewer pitched battles than expected.

Abu Jamal said 17 brigade fighters were killed in the conflict. For its part Hamas says it lost fewer than 50 fighters.

The Israeli Defense Forces puts the number of dead militants as high as "several hundred" and said 10 Israeli soldiers were killed.

Abu Jamal and his comrades say they believe they could have bogged the Israelis down in hand-to-hand urban warfare if they had pushed deeper into the cities. The Israelis say they halted the advance of the ground incursion when they did because they had achieved their main objectives.

Among the Israeli targets was the home of Abu Jamal. He briefly took me there as family members picked through the ruins. The IDF clearly had pinpoint intelligence on where he lived but he figured he was on their hit-list and had left along with his family. Now he was joking that having no home to return to would force him to spend more time with his "resistance" comrades.

When talk turned to the political reaction to the war, Abu Jamal and his fighters were clearly disgusted with what they saw as a lack of "brotherhood" from Arab neighbors but they did say they felt they'd discovered a new champion in an unexpected place: Venezuelan President Hugo Chavez. Chavez expelled the Israeli ambassador to Caracas and was forthright in condemning the Israeli offensive.

From that encounter with this cell of the Salaheddin Brigades it was clear their fighting resolve remained intact. For a guerrilla unit every day it survives is a victory of sorts in the face of the overwhelming firepower the Israelis had in their arsenal.

It's clear too the Salaheddin Brigades see their fight as a religious mission and that the recent conflict was just the prelude to a bigger fight they believe they will one day wage.

"In the past we threw stones and then had small guns," said Abu Jamal. "Now we will move forward until we finally bring all Muslims to pray in Jerusalem."