Survivors and victims of last year’s deadly blast in Beirut’s port joined rights groups on Wednesday to urge the United Nations Human Rights Council to establish an “independent, impartial, prompt, thorough, effective, reliable, and transparent” investigative mission into the Aug. 4 explosion that killed at least 218 people.

Prosecutors in Lebanon have charged the country’s transitional leader and three former ministers with negligently causing the death of hundreds of people, as well as injury to thousands more, aftera massive explosion rocked the capital of Beirut in August.