Elements of the 3rd Special Forces Battalion (SFB) indiscriminately shot at six Lumad-Manobos in Barangay Diatagon, Lianga, Surigao del Sur in the afternoon of June 15. The victims were identified as Willy Rodriguez, 32, Lenie Rivas, 21, and her 12-year old sister Angel Rivas. The victims are believed to have been tortured before being killed in cold blood. The Rivas siblings are also believed to have been raped before their genitals were repeatedly shot. Three other victims were able to escape.

The younger Rivas was a 6th grade student under the Alternative Learning System (ALS) of the Department of Education. Lenie Rivas and Rodriguez are members of Lumad na Malahutayong Pakigbisog alang sa Sumusunod (MAPASU). They were all residents of Sitio Manluy-a.

The 3rd SFB attempted to cover up by claiming that the victims were Red fighters. Soldiers of the 3rd SFB and 48th IB have long been occupying Sitio Panukmoan in Diatagon to evict residents from their communities to pave way for the entry of big mining companies in Andap Valley.

Progressive groups protested in front of the Commission on Human Rights in the afternoon of June 17 to condemn the massacre. This is the 25th massacre under the Duterte regime, and second in Diatagon.