A deadly shootout between Sri Lankan soldiers and militants believed to have ties to the Easter Sunday bombings that killed more than 250 people broke out late Friday night in eastern Sri Lanka.

When the dust settled, the bodies of six suspects were recovered, as well as those of 10 civilians, six of whom were children. At least three explosions were reported during the firefight, leading some to suggest that not all of the civilian casualties resulted from the shootout, and that some may have fallen victim to suicide bombers within the militant group. At least one civilian woman who was killed just happened to be passing by the scene in a small rickshaw.

Earlier that same day, authorities seized a large cache of explosives alongside more than 100,000 ball bearings—often included in improved explosive devices as projectiles to increase the lethality of an explosion—just miles away from the location of the shootout. Also discovered in the cache were ISIS flags and uniforms. Thus far, the local extremist group National Thowheed Jamath has been linked to the attacks, though they have not formally claimed responsibility and ISIS has. That, however, may not indicate formal ISIS involvement, as the group has a long track record of claiming responsibility for any attacks that are even tangentially related to their cause for the sake of expanding the perception of the global threat they pose.

One of the six suspects’ bodies recovered after the shootout on Friday night was that of Mohamed Niyas, a prominent member of National Tawheed Jamath. In fact, authorities now believe it was Niyas’ brother-in-law, Zahran Hashim, who masterminded the coordinated bombings that claimed the lives of 253 people—mostly Christians—last Sunday.