Iraqi commanders say troops moved into the Muharabeen and Ulama neighborhoods after fully liberating the adjacent Tahrir neighborhood on Friday.
They said ISIS militants were fighting back with snipers, rocket-propelled grenades and mortar rounds.
Footage taken by Rudaw TV, an Iraqi Kurdish channel, showed smoke from explosions rising above the city skyline as heavy gunfire could be heard, while Iraqi soldiers and armored vehicles tried to advance through the narrow streets of the city.
Shortly before noon, a suicide bomber emerged from a house in the Tahrir neighborhood and attacked security forces, wounding four troops. Later in the afternoon, another suicide car bomber hit the troops in the Aden neighborhood, killing a soldier and wounding three others, AP reported.
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