U.S. Attorney General Jeff Sessions asked the remaining U.S. Attorneys appointed by Barack Obama to resign on Friday.

Damon Martinez, the U.S. Attorney from New Mexico, resigned Friday, according to a statement from his office. First Assistant U.S. Attorney James D. Tierney is the Acting U.S. Attorney until a new U.S. Attorney is confirmed by the U.S. Senate.

A U.S. Department of Justice spokeswoman announced in a statement Friday afternoon “many” of the Obama-nominated U.S. Attorneys had already left their positions.

“The Attorney General has now asked the remaining 46 presidentially appointed U.S. Attorneys to tender their resignations in order to ensure a uniform transition,” Sarah Isgur Flores said. “Until the new U.S. Attorneys are confirmed, the dedicated career prosecutors in our U.S. Attorney’s Offices will continue the great work of the Department in investigating, prosecuting, and deterring the most violent offenders.”

Martinez himself was a replacement for Kenneth Gonzales, the first New Mexico U.S. Attorney oppointed by Obama. Gonzales went to a federal judgeship in 2013.

A purge of U.S Attorneys is not unusual during a president’s new term.

Gonzales wasn’t appointed until 2010, and he took over from Greg Fouratt, who is now a U.S. Magistrate judge.

The U.S. Attorney’s position in New Mexico became controversial when Fouratt’s predecessor, David Iglesias, was fired by President George W. Bush in 2006. Republican officials, including then-Republican Party of New Mexico chairman Allen Weh, then-U.S. Senator Pete Domenici and then-U.S. Rep. Heather Wilson, allegedly pushed for Iglesias’ ouster.

Update: Added confirmation that Damon Martinez resigned.