Daesh is building a moat around Mosul in northern Iraq in preparation for a long, hard battle against US-backed Iraqi government forces for the biggest city still in their possession, Reuters reported yesterday.
According to the report, Daesh has been working hard this month to dig a two-metre by two-metre trench along the city's perimeter and position oil tanks nearby to create a "river of fire" that would impede advancing troops and hinder aerial surveillance.
The Mosul trench is an innovation on a previous tactic Daesh used in Tikrit and Qayyara, where they set oil wells ablaze in order to create a black smog that would deter Iraqi close-air support from airstrikes that may hit their own units.
Last month, Iraqi security sources claimed that Daesh had plans to pump large quantities of oil into the Tigris river before setting it on fire in order to hamper the Iraqi military and allied militias from advancing north towards Mosul. This failed to materialise, suggesting that the Mosul "river of fire" report may be misinformation.
Human shields and tunnels
Speaking on condition of anonymity, residents have confirmed to MEMO the presence of extensive tunnel networks throughout the city. They added that Daesh is positioning its units in between residential homes.
"Daesh fighters are now positioned directly amongst the people," Um Omar told MEMO, adding: "Are they trying to deter the Americans and [Iraqi] government from bombing us? They know that we will be bombed along with them as the government doesn't care, so I don't see the point."
Michael Stephens, a security expert at the London-based Royal United Services Institute, said that Daesh is likely embedding amongst civilians in order to tactically restrict coalition forces, specifically air assets.
"It's been a pattern for [Daesh] units to embed amongst civilians since coalition airstrikes first began," Stephens told MEMO, "Clearly, the issue of rules of engagement is a complex and sensitive matter that has restrictive effects on the ability of coalition forces to fight the group. The reasoning is primarily tactical and unfortunately rather successful."
Another resident and former soldier, Abu Ali, told MEMO that tunnels are sometimes hidden in houses and the only people who know where they are and where they lead to are Daesh fighters and smugglers.
"There are tunnels all over the city, and people are saying that some have been mined in order to set ambushes and traps for Iraqi troops and militias that may penetrate into Mosul," Abu Ali explained.
Reuters reported another resident as saying: "I can see Daesh digging tunnels everywhere and covering the entrances with sewage covers. My neighbour's house is now part of a network of tunnels that reaches across the city."
"Oil trenches, tunnels and suicide attacks will not save Daesh from defeat but they will make the battle more challenging," Sabah Al-Numani, a spokesman for the counter-terrorism forces which are expected to spearhead the offensive, told Reuters. "We are confident Daesh will fight to their last fighter to keep holding Mosul."
In addition to the moat, Daesh has sealed off central districts of Mosul with cement blast walls and dozens of trucks were seen earlier this month carrying similar barriers into the city's airport which could be used as a staging ground for airborne attacking forces.
Prime Minister Haidar Al-Abadi has repeatedly vowed to retake Mosul by the end of the year and Iraqi forces yesterday launched an operation to retake the northern town of Shirgat.