The IOC is telling Olympic athletes they may not wear armbands or stickers during competition to commemorate the dead.
The Olympic body said Monday it sent a letter to Norwegian Olympic officials after four female cross-country wore black armbands in memory of an athlete's brother who died on the eve of the games.
The International Olympic Committee also told freestyle skiers not to wear stickers on their helmets in tribute to Canadian halfpipe skier Sarah Burke, who died after a crash in training two years ago.
"We would say the competitions themselves, which are a place of celebration, are probably not the right place to really do that," IOC spokesman Mark Adams said. "We would like to keep that separate."
Burke died Jan. 19, 2012, nine days after a training accident on a halfpipe in Park City, Utah. She was 29.
Burke lobbied hard for inclusion of all the freeskiing disciplines for women in the X Games and, ultimately, the Olympics. Some athletes had wanted to wear helmet stickers in tribute but were turned down by the IOC.
Adams said the IOC has "huge sympathy" for Burke and is willing to helping athletes remember her at news conferences or a ceremony at the multifaith center in the Olympic Village - but not at the competition sites.
"We really think she is an important person to be remembered," he said.
The Norwegians wore black armbands in Saturday's 15-kilometer skiathlon, the opening cross-country event of the games.
The Norwegian Olympic Committee received a letter from the IOC saying the gesture goes against rules which prohibit the wearing of messages on Olympic uniforms or equipment. The IOC told the Norwegians not to do it again.
Adams did not elaborate on the letter, saying that was "the end of the matter."
Inge Andersen, secretary general of the Norwegian Olympic Committee, said he was upset at the decision and planned to take the issue to the "highest levels" of the IOC.
"We want to discuss why the IOC don't want to let us go through this tragedy in a normal manner," he told The Associated Press. "That would be normal in every other society. It's about the Olympic movement. We are all human beings. We have to take care of each other."
The younger brother of Norwegian skier Astrid Uhrenholdt Jacobsen, Sten Anders Jacobsen, died "suddenly and unexpectedly" on Friday, the Norwegian team said, without elaborating.
The next day, Marit Bjoergen won the skiathlon for her fourth Olympic gold medal, with teammates Heidi Weng taking the bronze and Therese Johaug finishing fourth. The four Norwegian teammates - including Kristin Stoermer Steira - all cried as they embraced each other after the race. Bjoergen and Weng wept on the podium during the flower ceremony.
The Norwegians said Monday they wouldn't wear the armbands again. Bjoergen said she didn't regret the decision to do so Saturday.
"It was worth it," she said.
Sten Anders Jacobsen was his sister's training partner, and was well known within the close-knit Norwegian team, which spends a large part of the year together.
Jacobsen has remained in Sochi and is to compete in the individual freestyle sprint Tuesday.
Andersen, the Norwegian Olympic official, said he wasn't told in advance about the athletes' plan to wear the armbands. But, had he been asked, "I would have said yes."
"This is a tragedy for the whole team," Andersen said. "It is only human that they must be allowed to show that. It is part of their therapy to show respect both for the sister of the brother who died and the boy who died."
The IOC has strict rules against protests or propaganda during competitions, outlawing any demonstrations in Olympic venues. The IOC worries that allowing someone to display messages not tied to the games would encourage others to use the Olympics for their own gain.
Gerhard Heiberg, a senior IOC member from Norway and the chairman of its marketing commission, said the IOC had to stick by its rules, otherwise it would open a precedent.
"But as a Norwegian," he told the AP, "I must say I have full understanding of what happened. These four girls in the race they were really concerned. They wanted to show their sympathy. As a person I have a full understanding for it, but as an IOC member I can see that the consequences are not good."