An underground world in the Ukraine capital is made up of Soviet-era bomb shelters, bunkers and basements. A potential Russian attack threatens to put the bygone shelter system to the test.

"The enormity of the situation ... the pain of it all, is pretty insane," Zhou said in an emotional video posted to Instagram. A silver medalist in the team event, he was to compete again on Tuesday.

In a carefully-managed interview with a French magazine, Peng also said she was retiring from tennis and said her private life should not be brought up in politics or sport.

Shiffrin, known as the reigning queen of the slopes, fell in her first run in the giant slalom at the Beijing Olympics. It was the first time she did not finish a giant slalom race in four years.