Efforts are underway to rebuild the ancient city of Nimrud in northern Iraq which was destroyed by the Islamic State (ISIS) in 2015, Iraq's culture minister told Rudaw on Sunday.

"More than 35 thousand archeological pieces have been recovered," Ahmed Fakak al-Badrani said, noting that a "scientific approach" is being used to identify both damaged and intact artifacts for preservation.

In June 2014, ISIS launched an all-out offensive in northern and western Iraq, seizing large swathes of territory, including the city of Mosul in Nineveh province, which the group declared as the capital of its proclaimed Caliphate between Iraq and Syria.

During its rule, ISIS targeted ancient sites, including Nimrud, for destruction.

Related: Timeline of ISIS in Iraq
Related: Attacks on Assyrians in Syria By ISIS and Other Muslim Groups

Citing idolatry, ISIS militants in March 2015 destroyed numerous relics in the ancient city, including cuneiform tablets and statues, using sledgehammers and power tools before demolishing the entire city with large explosions, claiming it was "un-Islamic." Iraqi forces recaptured the ancient city in late 2016.

The destruction of Nimrud city drew widespread condemnation, with the United Nations Educational, Scientific and Cultural Organization (UNESCO) calling it a "war crime".

Badrani on Sunday stated that Baghdad has yet to "determine the number of artifacts stolen" during the ISIS attacks on Nimrud. The culture minister additionally confirmed the involvement of international experts in recovering the stolen pieces and praised the "enthusiasm and dedication" of the archaeological teams working on-site, calling their efforts "uplifting."

Located 32 km south of Mosul and 360 km north of Baghdad, Nimrud was the capital of the Assyrian Empire between approximately 1250 BC and 610 BC during the reign of Ashurnasirpal II in the 9th century BC.

In addition to being a significant political center, the city was known for its grand palace, intricate stone carvings, and monumental sculptures, showcasing the architectural and artistic achievements of the Neo-Assyrian period, according to UNESCO.

For his part, Ali Ismail, who works at Nineveh Antiquities and Heritage Office, told Rudaw on Sunday that the artifacts are being extracted with "utmost precision and caste to avoid causing any damage." He noted that the work is progressing slowly due to the risk of "explosive devices and barrel bombs at the site" that might still be at the site.

"However, despite the hardships our goal is to retrieve the largest number of artifacts possible so that we can begin rebuilding the grand palace in the next phase," Ismail said.