Michigan officials have discovered unexploded bombs and two more bodies, with more victims feared missing under the rubble

Emergency crews have discovered two more victims in the ruins of a Mormon church set ablaze during Sunday's shooting in Michigan, raising the death toll to four parishioners, in addition to the gunman killed in a shootout with police.

Grand Blanc Township Police Chief William Renye told reporters that two of the victims had gunshot wounds.

"Including the suspect, there are five deceased persons from this tragic incident," he said, praising first responders who arrived at the church within 30 seconds of the first 911 call. Seven people remain hospitalized in stable condition, while one is in critical care.

Crews are continuing to comb through the debris of the destroyed church, which Renye described as "a total loss due to the fire." He added that some people remain unaccounted for. "We are in recovery mode," he said.

Investigators revealed that the suspect, identified as 40-year-old Thomas Jacob Sanford of Burton, used gasoline as an accelerant to ignite the fire. Sanford was a former Marine sergeant who served in Iraq between 2007 and 2008. According to the Marine Corps, he had received multiple service awards, including the Iraq Campaign Medal and the Marine Corps Good Conduct Medal.

The ATF also discovered several suspected explosive devices at the site, though it was not immediately clear whether they had been used to start the blaze, according to special agent James Deir. Michigan State Police reported receiving additional bomb threats at churches and other locations in the area.

Authorities have not disclosed a possible motive. The FBI is leading the investigation and said it is treating the shooting as "an act of targeted violence." NBC affiliate WDIV reported a heavy police presence at a residence believed to be Sanford's home.