A group of 36 lawmakers led by Senator Elizabeth Warren has called for an investigation into Immigration and Customs Enforcement's online detainee tracking system, describing it as "increasingly unreliable" in a letter to the Department of Homeland Security's inspector general.

The lawmakers characterized the situation as creating "disappearances" on U.S. soil due to problems with the Online Detainee Locator System (ODLS), which has been used for years by family members, attorneys, and journalists to track people held in the federal immigration detention system.

Separately, Reuters reported that ICE arrested more than 800 people following tips from a U.S. airport security agency, though the timeline and connection to the tracking system concerns were not specified.

The calls for investigation come amid other recent immigration enforcement activities. Far-right media figure Laura Loomer claimed credit for the arrests of relatives of former Iranian General Qasem Soleimani, who was killed in a U.S. strike in Iraq in 2020. The relatives, described as Soleimani's niece and grandniece, were reportedly arrested by ICE agents in California.

The DHS has not immediately responded to requests for comment regarding the lawmakers' concerns about the detainee tracking system or the various arrest reports.