04/24/2014 10:27 am ET Updated Apr 24, 2014

Chris Hayes Calls For Immediate Release Of Vice Journalist

Chris Hayes is calling for the immediate release of the Vice reporter currently detained in Eastern Ukraine.

Simon Ostrovsky, a Vice News correspondent who has been covering the ongoing crisis in Crimea and Ukraine, has been held captive by pro-Russia separatists since Tuesday. The U.S. State Department called on Russia on Wednesday, urging the release of Ostrovsky and asking for the "immediate and safe release of all hostages in eastern Ukraine."

Hayes sent a strong message to the militia holding Ostrovsky Tuesday night:

Whoever is holding him, know this: you cannot detain him and expect no one to notice. Because we, right here on this show, in this country and around the world are watching. We are all watching what you do and we will all continue to watch until you release him, which you should do immediately.

Hayes has continued to dedicate a segment of "All In" to demanding his release, and he said that he will not stop until Ostrovsky is free. Hayes added that his show has been "relying" on Ostrovsky "for his incredibly insightful reporting."

On Wednesday night's broadcast, he added: "We will continue to monitor Simon's situation until he is returned home safe and sound, which as I said last night, should be immediately."

Watch the video to see Hayes' aggressive call for action.