The first information report of the Dera Ismail Khan attack was filed on Wednesday at the Counter Terrorism Department police station, DI Khan Region I in Khyber Pakhtunkhwa.
The report named unidentified members of the outlawed TTP and their mastermind as the suspects behind the attack.
The FIR invoked Section 7ATA (Punishment for acts of terrorism) and Section 302 (Punishment of qatl-i-amd), Section 324 (Attempt to commit qatl-i-amd), and Section 353 (Assault or criminal force to deter public servant from discharge of his duty).
The report also invoked Section 3 (Punishment of offences committed beyond, but which by law may be tried within Pakistan), Section 4 (Extension of Code to extra-territorial offences), Section 5 (Certain laws not to be affected by this Act), Section 148 (Rioting, armed with deadly weapon), Section 149 (Every member of unlawful assembly guilty of offence committed in prosecution of common object), and Section 427 (Mischief causing damage to the amount of fifty rupees) of the Pakistan Penal Code.
In the deadliest incident, at least 25 soldiers were martyred while 27 terrorists were killed in three different gun battles, one of which followed a massive suicide attack on December 12.
The three incidents occurred in three different areas of DI Khan district in the Khyber Pakhtunkhwa, according to the Inter-Services Public Relations (ISPR).
The terrorists rammed an explosive-laden vehicle into a security post in the Daraban of DI Khan after failing to enter the post in the first attack.
The checkpost building collapsed in the explosion, leaving 23 troops martyred. A gun battle ensued and six terrorists were killed.
Two other soldiers were martyred in a gun battle in the Kulachi area of the district. The exchange of fire left four terrorists dead. The third gun battle occurred in the Darazinda area and left 17 terrorists dead.