Israel ordered the evacuation Wednesday of large areas of Gaza's main southern city, the United Nations said.

The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said Israel had released maps showing new areas covering about 20 percent of the Khan Yunis city that had been marked for evacuation.

Before fighting broke out, the area was home to more than 110,000 people, OCHA said.

The area also includes 32 shelters that housed more than 140,000 internally displaced persons, the vast majority of whom were previously displaced from the north, it added.

The Israeli army said Wednesday that "ground, aerial and naval operations were carried out on dozens of terrorists and terrorist infrastructure" on military command and control centers in Khan Yunis.