Elizabeth Throssell, spokesperson for the UN High Commissioner for Human Rights, condemned on Thursday a Russian airstrike on a village in the eastern Ukrainian region of Kharkiv that killed at least 51 civilians. In a press release from Geneva,  Throssell reiterated the importance of “strictly respecting” international humanitarian law.

According to an OHCHR press release, the UN High Commissioner for Human Rights, Volker Türk, is deploying a field team to the attack site. He is opening a probe to gather information on the attack by investigating the site and speaking to survivors in Hroza. In his own statement Thursday, Ukrainian President Volodymyr Zelenskyy emphasized the importance of Ukraine “strengthening its air defense to better protect Ukrainians from Russian terror attacks, similar to the one in Kharkiv.”

What appears to be a Russian missile struck a café and grocery in the village of Hroza in the Kharkiv region on Thursday, resulting in at least 51 deaths. The UN is calling the attack “one of the deadliest.” Moscow is denying that it targeted civilians. However, a block of flats in Kharkiv was hit by a Russian missile Friday, claiming at least 20 lives, including that of a ten-year-old.

International humanitarian law sets out rules to create protections and mitigations during armed conflict. It serves to protect civilians and imposes restrictions on methods of warfare. Importantly, it prohibits the use of torture and violence against civilians or those who are not engaging in armed conflict. The key treaties are the 1907 Hague Regulations and the Geneva Convention. Importantly, part III of the Geneva Convention sets out the status and treatment of protected persons.