Transcript for US Launches Airstrike in Iraq Against ISIS

This is an ABC news special. Crisis in Iraq. And good morning and Dan Harris -- -- briefly when news of an American air strike in Iraq the Obama administration taking military action in a war the president claimed to have ended several years ago just a short while ago. US military announcing it has carried out an -- to knock out artillery. Being used by Islamist militants and ABC's Martha Raddatz broke the news of this mission and she joins us now from Washington with the latest Martha -- now. Dan the president of course as you know authorized airstrikes last night they've already carried out humanitarian missions with air drops. That this airstrike just came a short while ago aimed at an artillery piece -- mobile artillery piece near -- -- Her -- is under great threat that is why the president chose to act Central Command carried it out with two F eighteen fighter jets dropping 500. Pound bombs on the artillery. They believed that Americans were threatened because there are Americans. In her BO and they do not want those ice his troops moving on her BO. I think you're going to see this as an ongoing mission in the coming days that if those ice -- convoys move as the president said last night they will also tried to strike those convoys. Been very difficult targeting this does crisis fighters those terrorists. In Northern Iraq through outer rock blend in with the civilian population so I think if if they -- targets of opportunity like they did this morning -- picked up. So got two things gone now we've got the -- -- fighters moving closer to air bill which is a city where there are a lot of Americans know we have this humanitarian crisis would the Christian community on top of the mountain surrounded by fighters how worried is the Obama administration right now -- being sucked back into this war that they claim to have. And did back in 2011. Well you heard the president say last night -- that we will not be sucked back into a larger war that there is no military solution. But being willing to even carry out these smaller air strikes really does put the US back in -- combat role. The president says there are no combat boots on the ground in this will not be large but we are in a combat role right now with airstrikes carried out there. Exactly the position the Obama administration did not want to be and Martha Raddatz thank you we're -- return out of our regular programming. In some parts of America that's Good Morning America there will be a complete wrap up tonight on world news -- Diane sore. And you get the latest news any time he won it on abcnews.com. For now I'm Dan Harris in New York. Have a great day. This has been a special report. From ABC news.

This transcript has been automatically generated and may not be 100% accurate.