WASHINGTON – Secretary of State Mike Pompeo's decision Friday to fire his department's inspector general marks the fourth time within the last three months that an internal agency watchdog has been targeted for removal by the Trump administration.

IGs are nominated by the president and confirmed by the Senate. Working within the agency they monitor, the inspector generals and their staffs are charged with reporting on government malfeasance and corruption.

Here's a look at the inspector generals who have been ousted recently:

State Department IG Steve Linick was appointed in 2013 during the Obama administration after serving other senior roles in the U.S. government.

A State Department official declined to say why Linick was fired, and the White House did not explain the move in a letter informing lawmakers.

But a Democratic aide, who was not authorized to speak on the record, said the IG was probing allegations that Pompeo used a political appointee at the State Department "to perform personal tasks for himself and Mrs. Pompeo."

Linick also oversaw the contentious investigation of then-Secretary of State Hillary Clinton's use of a private email server and criticized her actions in a 2016 report.