A powerful Syrian rebel faction has for the first time openly revealed that its forces were taught how to dig attack tunnels by Islamist terrorists in Gaza.

In a report for the pro-opposition Orient TV posted online earlier this month and translated by MEMRI, a reporter is given a tour of a tunnel dug by Ahrar al-Sham - an Islamist rebel faction which often fights alongside Al Qaeda's Nusra Front, and is considered one of the most prominent and powerful rebel forces in Syria.

The tunnel is located in Idlib province, where a rebel coalition including Ahrar al-Sham, called the "Army of Conquest," recently scored a series of victories against regime forces, seizing most of Idlib including its provincial capital.

During the report, a grinning rebel commander shows off a huge stash of explosives packed in the tunnel, and boasts of an imminent "earthquake" when the explosives - located beneath a regime position - are detonated.

Explaining how his forces managed such an impressive technical feat, the commander says: "We asked for the advice of our brothers in Gaza... They even sent me a video, and we did it exactly the way they do it."

Syrian rebels have repeatedly employed attack tunnels to strike at regime forces throughout the country, detonating tons of explosives under positions including command centers and other concentrations of pro-regime troops.

The rebel commander does not say which Gazan terrorist group he contacted, but reports Hamas was training Sunni rebels in Syria - and specifically instructing them on how to dig attack tunnels - first surfaced in 2013. An article in the UK's Times newspaper cited Syrian opposition sources who claimed that "several hundred" Hamas terrorists were operating out of the numerous Palestinian Arab "refugee camps" in Syria, and transferring their skills honed in warfare with Israel with their Syrian rebel counterparts.

The reports were contentious due to Hamas's complicated relationship with Damascus, and elicited a quick denial by Hamas at the time. Today, rebel factions linked to Hamas operate openly in places such as the Yarmouk camp on the outskirts of Damascus.

The confirmation that Syrian rebels are targeting Assad regime forces with tactics learned from groups such as Hamas and Islamic Jihad in Gaza contains no small measure of irony.

Those two factions - who control the Gazan tunnel network - are both funded, trained and equipped by Assad's key ally Iran.

But Tehran is also the key backer of the Assad regime, and many of the fighters targeted in rebel tunnel attacks belong to militias directly supported or even commanded by Iran, including Tehran's most important regional proxy Hezbollah.