DHS watchdog warns of 'urgent issue' after immigration officials allegedly lose track of unaccompanied children

The Department of Homeland Security's internal watchdog says it has uncovered an "urgent issue" with how immigration officials handle cases involving unaccompanied migrant children, warning in a new report that the Immigration and Customs Enforcement agency has been unable to keep track of all unaccompanied minors released from government custody.

The interim report, sent to Congress on Tuesday and obtained by ABC News, said that -- in the past five years -- more than 32,000 unaccompanied migrant children failed to appear for their immigration court hearings, and ICE was "not able to account" for all of their locations.