Over the weekend the Islamic State began auctioning off properties belonging to Christians.

In a move that may suggest the Islamic State is feeling the pinch of repeated airstrikes by the U.S.-led coalition on targets including ISIS-held oil refineries and cash reserves, the Islamic State’s police force announced an auction of properties formally held by Christians who fled when the terror group entered Mosul.

In total, 400 homes, 167 shops and 19 apartment buildings were shown and sold at low prices to quickly draw in funds, Al Sabah Newspaper reported.

Starting in June 2014, Christians living in Mosul were forced to pay a ‘Jizya,’ or minority tax or to leave their homes behind.

Others were killed before they were offered that decision.

Last week, a U.S. airstrike targeted and destroyed an ISIS money stockpile in Mosul, part of ongoing operations aimed at limiting the terror group’s cash flow.

ISIS still has many other revenue producing outlets including oil sales, the sale and looting of antiquities, human trafficking and the sale of natural resources and agricultural goods within ISIS territories, which can generate hundreds of millions of dollars.

Recent reports also suggest ISIS is profiting heavily from selling Yazidi women and other minorities as sex slaves and instances of organ harvesting have also been reported.