Updated

A recent military operation foiled an attempt to set up an organized Islamic State group base in the country's southwest, the Pakistani army said Thursday.

The Taliban-linked Sunni sectarian outfit Lashkar-e-Jhangvi Al-Almi was working to establish the IS foothold, the army said in a statement.

The three-day operation was conducted in a rugged mountain range near Mastung district in southwestern Baluchistan province and left 12 militants dead. Five soldiers were wounded, the army said.

An IS group claimed a suicide attack targeting a Pakistani lawmaker last month in the same district, which killed 25 people.

The military released images and video footage of the base spread over 10 kilometers (6 miles), which has a 250 meter (273 yard) long gorge with steep heights and multiple caves where the operation was started with an air-born commando force landing there first. Tough resistance resulted in a prolonged three-day fight, the military said.

A bomb-making facility in the base was destroyed by the army, which also seized 50 kilograms (110 pounds) of explosives, three suicide bombing vests, hand grenades, rocket launchers, machine guns, sniper rifles and communication systems, the army said.

The suicide bomber who targeted the lawmaker had been sent from this base, said Pakistani army spokesman Maj. Gen. Asif Ghafoor. The sectarian group was making efforts to develop a communication system with the Islamic State group and facilitate establishment of its foothold in the country, he said. The operation has denied establishment of any direct or indirect IS group organized infrastructure, Ghafoor said.

Pakistan has denied any organized presence of IS in the country, but says some local militant groups have started using its brand name. Some Pakistani sectarian groups have in recent months partnered with the IS group in spectacular attacks, including a shrine bombing that killed 90 devotees.

The southwestern province of Baluchistan where the base was dismantled borders Afghanistan and Iran.