At around 10:30 in the morning of June 11, 2015, an encounter between government troops and lawless group occurred in Tamban-Tamban sitio of Barangay Bud Taran, Indanan, Sulu after launching offensive military operation started from Barangay Bato-Bato and Barangay Kuppong. Langpas Elementary School headed by Hja. Nalda J. Muksan, Head Teacher - III is just about one and a half kilometers away from the area of the encounter. Langpas Elementary School is the furthest school of Indanan South District towards west. It was during sharing and discussion over the preparation of 1-Day District Post Conference at ISD Office, Km. 2, Kajatian, Indanan, Sulu when one of the teachers from Mukammali Elementary School called on her school head, Melda I. Adug, Head Teacher - III informing her about the incident and requesting the hired tamaraw vehicle should immediately fetch Langpas Elementary School teachers before escalation of the conflict would take place. Mukammali Elementary School teachers are in the same hired tamaraw with Langpas Elementary School teachers from Jolo and vice versa in time of reporting to their respective stations from Monday to Friday,
The DIC asked Hja. Nalda J. Muksan to prepare letter of information to the division office about the happening in the mountain near Langpas Elementary School.
"Let us monitor the situation of the residents in Barangay Langpas starting this afternoon until Monday," the DIC advised the two school heads and teachers. "If the people will evacuate to Barangay Poblacion and Mukammali Elementary School, we must go there and open the classrooms for them," the DIC added. He also informed the teachers of Langpas Elementary School and Mukammali Elementary School to report to the ISD Office on Monday if the situation would come to worse.
The DIC also briefed Alyasir A. Hussam, TIC of Poblacion Elementary School to prepare his school for evacuees from Barangay Langpas and other barangays near the spot where the incident took place. In the afternoon, the TIC of Poblacion Elementary School and Annex passed by the DIC reporting the normality of the people in the neighborhood of the school. As he observed, there was no even single family from Barangay Langpas coming into Barangay Poblacion for evacuation.