By Stephen Kalin and Ahmed Rasheed
MOSUL, Iraq/BAGHDAD (Reuters) - Iraqi special forces closed in on the Tigris river that runs through central Mosul on Saturday, advancing in parallel with other troops and forcing Islamic State to retreat in its last major stronghold in the country.
Turkey and Iraq meanwhile came to an agreement over a demand for the withdrawal of Turkish forces from an area close to Mosul, Baghdad said, as the two regional powers sought to improve ties after a spat last year over Ankara's military deployment.
Turkey's prime minister did not say a deal had been reached, but that the issue was discussed and would be resolved.
Advances by Iraqi forces in recent days, including Saturday's push to within several hundred meters (yards) of the Tigris, involved an unprecedented nighttime assault by elite forces and have driven the ultra-hardline militant group out of several areas east of the river.
The U.S.-backed operation to drive Islamic State out of Mosul, which began in October, initially progressed well before slowing towards the end of the year amid fierce IS resistance and the presence of large numbers of civilians. It has picked up momentum again in a new phase launched last week.
Counter-terrorism service (CTS) forces were the closest they had been to the Tigris inside Mosul and closing in on a strategic bridge, supported by new tactics and better coordination, their spokesman said.
"Counter-terrorism forces have been sent about 500m from the fourth bridge," Sabah al-Numan told reporters east of Mosul.
CTS seized the Ghufran district, previously known as al-Baath, and entered neighboring Wahda, he said.
A separate military statement said Iraqi federal police had recaptured a hospital complex in Wahda in southeastern Mosul, a significant turnaround after army units were forced to withdraw from the site last month.
CTS and federal police "are now moving in parallel on both axes" in southeastern Mosul, Numan said.
"We are proceeding side by side ... and advancing at the same level. This is a very important factor, thanks to which Daesh (Islamic State) has not been able to move its fighters. It has to support one axis (front) at the expense of another.
"We have worn down the terrorist organization with this type of advance."
TURKISH WITHDRAWAL DISCUSSED
Friday's nighttime operation, launched after a week of planning, had been a particular success, Numan said.
CTS forces using night-vision equipment crossed the Khosr river, a tributary that runs perpendicular to the Tigris through eastern Mosul, via makeshift earth bridges after IS had destroyed permanent ones, he said.
Air strikes from the U.S.-led coalition sped that advance into Muthanna district.
The CTS and federal police are part of a 100,000-strong Iraqi force made up of the military, Kurdish fighters and Shi'ite militias, backed by U.S.-led air power.
Some Sunni Muslim and Kurdish peshmerga units have been trained by Turkish forces stationed at the Bashiqa camp northeast of Mosul.
Turkey's military presence in northern Iraq since well before the Mosul campaign has angered Baghdad, and the two countries traded barbs over the issue in October shortly before it began.
Prime Minister Haider al-Abadi said Baghdad reached an agreement with Ankara on Saturday over Iraq's request that Turkish forces withdraw from Bashiqa.
He gave no details of the deal, which he announced during a visit to Baghdad by Turkish Prime Minister Binali Yildirim. Turkey agreed to "respect the sovereignty of Iraq", and Baghdad and Ankara agreed not to interfere in each other's domestic affairs, he said.
Yildirim said at a news conference with Abadi: "We discussed the issue of Bashiqa.
"We see that significant progress is being made in cleansing Daesh from the region. In line with this we will solve this (Bashiqa) subject in some way in a friendly way."
(Reporting by Stephen Kalin in Mosul, Ahmed Rahseed and John Davison in Baghdad, Daren Butler in Istanbul; editing by John Stonestreet)