The United Nations says the number of humanitarian aid workers who have died in conflict zones around the world this year has reached 281, the highest on record.

The UN Office for the Coordination of Humanitarian Affairs, or OCHA, provided the figure in a report on Friday.

It says the death toll of the aid workers surpassed the previous record of 280 that was marked last year, and the number has been driven up by the fighting in the Gaza Strip.

A breakdown of the figures in the report shows 178 killed in the occupied Palestinian territory, including Gaza, 25 in Sudan, and 11 each in Ukraine and the Democratic Republic of Congo.

OCHA also puts figures for wounded aid workers at 165 and those kidnapped at 79, with the number the highest in Yemen at 20.

Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Tom Fletcher, who heads OCHA, issued a statement saying, "Humanitarian workers are being killed at an unprecedented rate, their courage and humanity being met with bullets and bombs."

He said states and parties to conflicts must protect humanitarians and uphold international law.