Shot nine times, by four men, 16-year-old Priya Basumatary lay bleeding for 24 hours before her body was removed.
The Assam State Commission for Protection of Child Rights has decided to register a case.
Dwimuguri is a forest village under Runikhata police station close to the international border with Bhutan.
The four missing persons have been identified as – Bakar Ali, Saddam Ali, Ataur Rahman and Rahul Amin.
The Assam Police team were in three vehicles and a tractor. Hussain suffered two bullet injuries on his head and one on his leg.
Bandhs cripple life; militants open fire on forces in Chirang.
Assam killings: One more killed, toll reaches 8
The official said the incident could be in retaliation to the death of an NDFB(S) cadre in Gossaigaon
The anti-talks faction of National Democratic Front of Boroland,headed by founder chairman Ranjan Daimary
A group of militants of the GNLA and NDFB were taking shelter at a Garo basti near Mendipathar.
Union Home Minister P Chidambaram said the Centre has directed the security forces to deal firmly with the anti-talk faction of the National Democratic Front of Bodoland.
The blasts were reported to be the handiwork of the anti-talks faction of the National Democratic Front of Bodoland (NDFB).
The Opposition in the Assam Assembly hit out at the Congress-led government of Tarun Gogoi for the serial attacks.
The NDFB warned the Centre and the Assam govt of retaliation if killings of its cadres continued.
Four persons,suspected to be militants belonging to the anti-talk faction of the National Democratic Front of Bodoland