The head of the United Nations children's agency has said that more than 100 children have been killed in Gaza since the October ceasefire.

"More than 100 children have been killed in Gaza since the ceasefire in early October," UNICEF spokesman James Elder told reporters.

Even though a ceasefire was established, the bombings have not stopped, causing casualties.

He said almost all of the deaths of the 60 boys and 40 girls were caused by military attacks, including airstrikes, drone strikes, tank and gunfire shelling, and some deaths from unexploded remnants of war.

The death toll is likely an underestimate as it is based only on deaths for which there is limited information, Elder said.