epa-efeUnited Nations

The United Nations paid tribute Friday to the 21 employees killed in this week's plane crash in Ethiopia, one of the worst tragedies for the world body in recent years.

Secretary-General Antonio Guterres placed a wreath in the victims' honor during a ceremony at UN headquarters in New York.

"They were from many agencies, with many areas of expertise, from the highest level in the hierarchy, to all kinds of functions in the UN," he said of the victims.

"Yet together they were also a mirror of the United Nations: women and men, some in the beginning of their careers, others closing in on retirement but each on an individual mission, at the same time together, representing our larger quest - doing their part to build a better world, brick by brick, deed by deed, day in and day out," the former Portuguese prime minister said.

"As we continue that mission, let us reflect on their lives, let us honor their service and let us be inspired by their extraordinary example," he said.

All 157 people aboard were killed when an Ethiopian Airlines Boeing 737 Max-8 crashed last Sunday minutes after taking off from Addis Ababa bound for Nairobi.

The UN entity most affected was the World Food Program, which lost seven workers in last Sunday's accident. The UN Refugee Agency and the UN Office in Nairobi each lost three employees in the disaster.

Guterres commemorated the others who died in the crash and extended condolences to their families, while expressing solidarity with the people and government of Ethiopia.

The ceremony concluded with a minute of silence.

Ethiopian Airlines Flight 302 carried a large number of representatives of international organizations and activist groups who were headed to Nairobi for the fourth session of the UN Environment Assembly.

As a safety measure, the UN has instructed its agencies not to booking flights on Boeing 737 Max 8 and 9 aircraft, which many countries, including the United States, China and most of Europe, have barred from their airspace pending an investigation of the causes of the crash in Ethiopia.