More than 9,000 people were recorded as displaced from west Mosul in north Iraq on Thursday, UN spokesman Stephane Dujarric said at a daily news briefing here.
"This brings the number of people displaced from west Mosul to over 264,000 since the start of the west Mosul military operation on 19 February," he said.
An estimated 334,000 people are currently displaced in total as a result of fighting in both east and west Mosul, according to the Iraqi authorities.
Mosul witnessed a fighting between the Iraqi government forces and Islamic State terrorists.
The Iraqi government force's advance toward Mosul came after the Iraqi Prime Minister Haider al-Abadi announced on Feb. 19 the start of an offensive to drive the extremist militants out of the western side of Mosul, locally known as the right bank of Tigris River which bisects the city.
Late in January, Abadi declared the liberation of the eastern side of Mosul, or the left bank of Tigris, after more than 100 days of fighting against the Islamic State militants.
However, the western side of Mosul, with its narrow streets and a heavy population of between 750,000 and 800,000, appears to be a bigger challenge to the Iraqi forces, according to the United Nations estimates.
Mosul, 400 km north of the Iraqi capital of Baghdad, has been under IS control since June 2014, when Iraqi government forces abandoned their weapons and fled, enabling IS militants to take control of parts of Iraq's northern and western regions.