Stage set for final offensive against ISIS

​Erbil /Baghdad : Islamic State militants have placed booby traps across the city of Mosul, dug tunnels and recruited children as spies in anticipation of an offensive to dislodge the jihadists from their Iraqi stronghold, Iraqis and US officials said. Mosul, home to up to 1.5 million people, has been the headquarters of Islamic State's self-declared caliphate in northern Iraq since 2014 and the militants are making complex preparations to prevent Iraqi security forces, backed by a US-led coalition, taking it back.

The battle for the city, expected later this month, will help shape the future of Iraq and the legacy of US President Barack Obama. Even if Islamic State is driven out, there is a real danger of sectarian strife, especially if civilian casualties are high in a mainly Sunni city wary of the Shi-ite led Iraqi government and the Shi'ite militias it depends on.

The jihadists, who swept into Mosul almost unopposed two years ago as Iraqi forces fled, have rigged its five bridges with explosives, prepared car bombs and suicide attackers and stepped up surveillance, according to four residents who spoke via telephone or social media. "They are digging in to fight for Mosul.

They are more cautious, shaving their beards to blend in with the population and constantly moving their headquarters around," said former finance and foreign minister Hoshiyar Zebari, Zebari, a senior member of the Kurdistan Democratic Party with access to intelligence on Islamic State movements in Mosul, and Col John Dorrian, a spokesman for the US-led coalition, both said the group was moving men and equipment through underground tunnels. "You see a fighter go in one place and pop up in another," said Dorrian. "The entrances are always exposed and those are a priority target."

Islamic State fighters have put up concrete embankments and are using concrete T-walls to block points of entry for the attacking force, he said. Mosul residents said the militants have also dug a two metre by two metre trench around the perimeter of the city to be filled with burning oil to make air strikes more difficult. Aid groups have expressed concern over the prospect that many civilians could be killed in the fighting. About 2,00,000 people are expected to flee within the first two weeks of fighting, said Lise Grande, the UN humanitarian coordinator for Iraq.

The planned coalition attack is part of a concerted assault that has reclaimed territory from IS in Syria, Iraq and Libya. The militants have recently lost control of the Iraqi cities of Falluja and Ramadi and are threatening to execute anyone discussing "liberation" in Mosul, according to residents and Sunni militia forces who spoke to relatives there. Iraq descended into civil war, mainly between Shi'ites and Sunnis, after a US-led invasion toppled Saddam Hussein in 2003, and some Sunni Arab tribal leaders and former members of Saddam's Baath Party support Islamic State.