Top lawmakers on the Senate Finance Committee are requesting an unclassified briefing on a database kept by Customs and Border Protection that tracked journalists and others in a large migrant caravan last fall.

The committee's chairman, Republican Chuck Grassley of Iowa, and its ranking Democrat, Ron Wyden of Oregon, sent a letter Monday to the head of the agency asking to be briefed by Thursday.

Customs and Border Protection compiled data on dozens of people that included passport and social media photos. The database had information on journalists, organizers of the caravan "instigators" and activists.

Customs and Border Protection officials say the department's independent watchdog is looking into the database, and stress that journalists are not targeted based on their occupation or reporting.