The Department of Defense has released footage of a recent U.S. airstrike in Iraq showing millions in Islamic State money obliterated after being hit with a pair of 2,000-pound bombs.

First reported by CNN, the 47-second, black-and-white video shows the Jan. 11 bombing of an Islamic State cash-distribution center near Mosul in northern Iraq. In the aerial shot, millions of dollars can be seen after the explosion either going up in flames or fluttering above the site.

Though U.S. officials said “millions” were destroyed, they did not elaborate on the type of currency or exact amount, according to the report.

Islamic State had been using the cash stockpile to pay fighters’ salaries and bankroll overall operations, U.S. officials told CNN. The group’s expenses include administrative costs tied to managing the cities and towns they have captured, purchasing equipment and weapons for fighting and producing propaganda videos.

See also:How much money goes to fighting and funding ISIS, in 2 charts

The group has been described by the Treasury Department as “probably the best-funded terrorist organization we have confronted.” When it comes to generating revenue, Islamic State is fairly diversified, profiting from black-market oil sales, the taxation of territories it has seized as well as extortion and kidnapping ransom. It also makes money off stolen farmland in Iraq and Syria, and antiquities it’s plundered from ancient sites.

Islamic State has looted up to $1 billion raiding banks in Iraq and Syria, and it’s made more than $500 million from illegal oil sales, said Adam Szubin, the Treasury’s acting secretary for terrorism and financial intelligence, in December. Unlike other terrorist organizations, only a fraction of the group’s funding comes from overseas donors, he said.

See also:The countries where ISIS finds support, in 2 charts

U.S. has allocated $6.2 billion for military operations against Islamic State so far, according to the Defense Department. A U.S.-led operation has been bombing Islamic State targets for more than a year. Here’s a look at the number of U.S. airstrikes in Iraq and Syria so far:

And here are the specific targets destroyed by those strikes.