On Saturday, militants affiliated with ISIS attacked a Sufi shrine in Pakistan’s Balochistan Province, killing at least 50 people and wounding an estimated 100 others. Despite repeatedly confirmations, the Pakistani government is trying to deny that ISIS was involved.

The attack involved Uzbek attackers who were apparently recruited by ISIS, along with fighters from the Lashkar-e Jhangvi (LeJ), an anti-Shi’ite militant faction which confirmed in comments that it teamed up with ISIS on this attack.

ISIS has been making a serious effort to build up its influence in both Pakistan and Afghanistan, and while they’ve already established a strong presence in Afghanistan, this attack may suggest the Pakistan buildup is continuing much faster than the government will admit.

ISIS is trying to use much the same tactics as in Afghanistan, trying to draw in disaffected Taliban commanders as well as using their substantial name recognition internationally to try to get smaller factions to pledge loyalty to them. If they are able to get close with both the LeJ and the Islamic Movement of Uzbekistan, as this attack suggests, they could quickly become a major player in Pakistan’s crowded collection of militants.