A person seized and held by someone (e.g., criminals) as leverage—commonly called a hostage.
犯人は銀行で数人の人質をとった。
The criminal took several hostages at the bank.
交渉が続き、人質は無事に解放された。
Negotiations continued and the hostages were safely released.
テロ組織が人質の身代金を要求したという報道があった。
There were reports that the terrorist group demanded ransom for the hostages.