The United Nations human rights chief said Monday that at least 102 civilians, including seven children, had been killed in Ukraine since Russia launched its invasion five days ago, warning the true numbers were likely far higher.

"Most of these civilians were killed by explosive weapons with a wide impact area, including shelling from heavy artillery and multi-launch rocket systems, and airstrikes," U.N. High Commissioner for Human Rights Michelle Bachelet told the U.N. Human Rights Council in Geneva, warning that "the real figures are, I fear, considerably higher."

The UN High Commissioner for Human Rights said the suffering in Ukraine was widespread.

"Millions of civilians, including vulnerable and older people, are forced to huddle in different forms of bomb shelters, such as underground stations, to escape explosions," she said.

Some 422,000 Ukrainians have fled their homeland, with many more displaced within the country, she told the Geneva forum, which earlier agreed to hold an urgent debate on Ukraine later this week.

"My thoughts go out to them and to all those across the world who suffer," she said. "The calls for peace and human rights that are coming from individuals all over the world warn us that our future must not be a world that has become unmoored from the jointly agreed obligations of international human rights law, and from the Universal Declaration of Human Rights."

Bachelet's comments came at the start of the U.N. rights council's main annual session, which began with a vote to host an urgent debate on the Ukraine conflict later this week.

Ukraine, which had requested the debate, is expected to present a resolution calling for an investigation into Moscow's violations in the country.

Russia had rejected Ukraine's request for the debate and demanded the issue be put to a vote, but a large majority of the 47 council members supported Kyiv's request.

U.N. Secretary-General Antonio Guterres said on Monday that the escalation of Russia's military operations in Ukraine was leading to rising human rights violations and that the global body was monitoring them with teams on the ground.

"The escalation of military operations by the Russian Federation in Ukraine is leading to escalating human rights violations," Guterres said in a recorded speech at the opening of the Human Rights Council in Geneva. "We must show all people in Ukraine that we stand by them in their time of need."

In the same speech, Guterres said that a report due to be published later on Monday by a U.N. panel on adaptation to climate change represented "another death knell for the world we know," and urged compliance with the 2015 Paris accord.