Iraqi security forces advancing north along the Tigris river towards Mosul reached the last major town before the city on Friday, a police commander said.
Major-General Thamer al-Husseini said federal police forces entered a district of Hammam al-Alil, about 20 km (12 miles) south of the Islamic State stronghold of Mosul which Iraqi army forces have been attacking for several days.
Islamic State fighters retreating north to Mosul have forced thousands of residents of villages and towns such as Hammam al-Alil to travel alongside them as human shields against air strikes, villagers have told Reuters.
The United Nations said the militants transported 1,600 abducted civilians from Hammam al-Alil to the town of Tal Afar west of Mosul on Tuesday, and took another 150 families from the town to Mosul the next day.
They told residents to hand over children, especially boys above the age of nine, in an apparent recruitment drive for child soldiers, U.N. human rights spokeswoman Ravina Shamdasani said.
“Our units entered the Salahiya district of Hammam al-Alil,” Husseini told Iraqi television. “We have Hammam al-Alil covered from more than one side and I think within hours we will be able to announce to the Iraqi people the clearing of Hammam al-Alil and surrounding areas”.