About 50 Bancroft Elementary School pupils, including students from about two dozen countries, and a group of children from foreign embassies put colorful ribbons on a "wreath of hope" at the District Building Thursday in an annual ceremony to celebrate "peace and fellowship in the family of nations."

The students were joined by representatives from about two dozen embassies whose children brought ribbons in the colors of their national flags.

The event, sponsored by the Mayor's International Advisory Council, took place in the City Council chamber as the Ballou High School chorus, male chorus and concert band performed Christmas carols and lullabies.

But the atmosphere of calm carried a special significance. Officials at the Northwest D.C. school said their pupils endured a great deal of tension and fear recently after three 5-year-old girls were accosted by an unknown man. Two of the girls were sexually assaulted.

"I think they understood the meaning of this Christmas ceremony" and took it to heart, said Vivian Hairston, a school resource coordinator for the gifted and talented. "I think for them, it goes a lot deeper than just receiving gifts."

Margaret Crawford, a Bancroft counselor, said the sexual assaults created "a very tense moment for the faculty and students and community, but things are peaceful and settled now. Life must go on."

Harold McClinton, deputy mayor for economic development, said, "It is my sincere hope that this wreath, and the love that it represents, will so inspire us that we will renew our commitment to peace and to fellowship in the family of nations.

"The green branches of this wreath represent the ever-fresh possibilities of a world in which all go to sleep well-nourished and rise up to a day of material and spiritual fulfillment, and a world in which children are no longer the victims."

Henry Turpin, first consul at the Embassy of Senegal, looked around the room at the bright faces of children and teen-agers of various races and nationalities and smiled. "This is more than just symbolism. This shows that we are all concerned about the future of the world and that people ought to stand together for peace, love and understanding."

Other embassies represented at the event included those of Brazil, Cameroon, Cuba, Germany, Malaysia, Mozambique, Nicaragua, Pakistan and Turkey.

Ballou chorus singers Latonia Fields, 15, and Ralph Fox, 18, said they were happy to be included in the ceremony.

"Music helps relieve your tension and puts you at peace," said Fields, a sophomore.

"This event was important because it represents peace with other countries. There should be peace, not war," Fox said.