People lay flowers and toys at an entrance of Pulkovo airport outside St. Petersburg, Russia, during a day of national mourning for the plane crash victims, on Sunday, Nov. 1, 2015 (AP)

People lay flowers and toys at an entrance of Pulkovo airport outside St. Petersburg, Russia, during a day of national mourning for the plane crash victims, on Sunday, Nov. 1, 2015 (AP)

A woman places flowers outside the Russian embassy in Minsk, Belarus for victims of a Russian airliner which crashed in Egypt, November 1, 2015 (Reuters)

A woman places flowers for victims of a Russian airliner which crashed in Egypt, outside the Russian embassy in Minsk, Belarus, November 1, 2015 (Reuters)

A white paper plane with the writing reading "Condolences to relatives from Kiev residents" lays among flowers in front of the Russian Embassy brought by Ukrainians to pay tribute to victims of a Russian plane crash in Kiev, Ukraine, Saturday, Oct.31, 2015 (AP)

Ukrainians lay flowers to pay tribute to victims of a Russian plane crash in front of the Russian Embassy in Kiev, Ukraine, Saturday, Oct.31, 2015 (AP)

Children toys, flowers and candles brought by Ukrainians to pay tribute to victims of a Russian plane crash are seen at the Russian Embassy, in Kiev, Ukraine, Saturday, Oct.31, 2015 (AP)

A Ukrainian man lights a candle to pay tribute to victims of a Russian plane crash in front of the Russian Embassy in Kiev, Ukraine, Saturday, Oct.31, 2015 (AP)

A Ukrainian woman lights a candle to pay tribute to victims of a Russian plane crash, in front of the Russian Embassy in Kiev, Ukraine, Saturday, Oct.31, 2015 (AP)

Women light candles for victims of a Russian airliner which crashed in Egypt, outside the Russian embassy in Kiev, Ukraine October 31, 2015 (Reuters)