Col. Mohammad Shumari, head of civil forces working in the area, told CNN that 141 bodies had been removed from the location of the March 17 strike in the al-Resala district of Mosul's al-Jadidah neighborhood. The military investigation was ordered by Lt. Gen. Stephen Townsend, the commander of US and coalition forces in Iraq and Syria. It will look into US airstrikes that took place over several days -- roughly between March 14 and March 23.
"Since we believe a coalition strike contributed in at least some way to the civilian casualties, Lt. Gen. Townsend has directed that the civilian casualty assessment move directly to a formal 15-6 investigation for all allegations in the al-Jadidah neighborhood on or around March 17," Col. Joseph Scrocca said when he briefed reporters Thursday via a phone call from Baghdad.
A "15-6" is the designation of the Army regulation that governs such an investigation. The inquiry will be led by Brig. Gen. Matthew Isler, who helps oversee air support operations in Iraq.
"Obviously this is a very serious incident, we want to make sure we get it right and the best way is to have a general officer look at all of this holistically and answer the questions the commanding general wants answered," Scrocca said.
A defense official told CNN that Townsend decided to order the investigation after the military's forensic team returned from the site. The team went to the exact grid, saw the house and determined that there was evidence the US was in part responsible for bringing the house down, because the US did strike the house.
The official said they are looking at any other factors that might have played into this.
The US is well aware ISIS tries to deceive US targeting. Now that this has occurred the US believes it can develop some 'indicators" of when civilians are present, but the official declined to specify details due to security concerns.
Iraqi prime minister mentioned airstrike
The more formal investigation announcement was first mentioned by Gen. Joseph Votel during his Wednesday testimony before the House Armed Services Committee.
A person familiar with a Wednesday phone call between President Donald Trump and Iraqi Prime Minister Haider Abadi, said the Iraqi premier did raise the subject of the strike and civilian deaths.
However, this person would not say whether Trump apologized or expressed regret for the incident. The White House's official readout of the call did say the President "praised the remarkable bravery and sacrifices of the Iraqi people in our shared fight against terrorism."
A senior military official who briefed reporters Wednesday said that in the last week alone, coalition aircraft had dropped over 700 munitions and coalition artillery had fired some 400 rounds in support of Iraqi troops battling ISIS for Mosul.
Officials point to new ISIS tactic
Military officials have pointed to a new ISIS tactic of forcing civilians into buildings as one of the reasons for the potential recent increase in civilian casualties.
"What you see now is not the use of civilians of human shields, now it is something much more sinister," Scrocca said. "ISIS is smuggling civilians into buildings so we won't see them and trying to bait the coalition to attack, to take advantage of the public outcry and deter action in the future."
Scrocca said that the coalition had observed this tactic Wednesday via video surveillance.
"For the first time we caught this on video yesterday as armed ISIS fighters forced civilians into a building, killing one who resisted, and then used that building as a fighting position against the (Iraqi Counter Terrorism Service)," he said.
Scrocca said that the coalition was making adjustments in the wake of this new threat but would not elaborate due to operational security reasons.