The 22 Navy SEALs killed when their helicopter was shot down in Wardak province were part of a mission to go after a known Taliban leader directly responsible for attacks against American troops, two U.S. military officials have told CNN.

Get up to date on the incident that happened Saturday in Afghanistan

According to new information CNN's Barbara Starr obtained, the SEALs who were killed had been called in to assist another unit on the ground pinned down in a firefight. The officials did not know if the Taliban leader had been killed. They declined to be identified because of the sensitivity of ongoing operations in the crash area.

Coalition forces remain at the crash site in order to remove all the wreckage, and prevent insurgents from taking photos of the scene to use as a "propaganda tool," one official said. Investigators will be examining the wreckage, but the same official said the crash was catastrophic that there may be little to glean from it. The United States had specific reports of enemy weapons activity in the same area at the time of the crash, so officials continue to assume that the Chinook was shot down. One of the officials also said that while the Chinook helicopter has been described as a "conventional" aircraft, it did have all the latest electronic equipment and that the crew had special operations training.