WASHINGTON — The US government on Friday slapped sanctions on a high-profile Afghan money exchange house and its executives, accusing them of laundering cash for drug traffickers.

The Kabul-based New Ansari Money Exchange as well as 15 related people and firms were accused of hiding "illicit narcotics proceeds" in billions of dollars they transferred in and out of Afghanistan between 2007 and 2010.

The New Ansari Exchange was thought to be the biggest of Afghanistan's "hawala" money-transfer firms, which play an even larger role in the war-torn nation's economy than commercial banks.

As early as 2009 the US government had suspected New Ansari of involvement with drug dealers as well as insurgents and Afghan political corruption.

"Information strongly suggests Afghanistan's New Ansari hawala network is facilitating bribes and other wide-scale illicit cash transfers for corrupt Afghan officials," said an October 2009 State Department cable, leaked to WikiLeaks.

The cable from the US embassy in Kabul added that the group was "providing illicit financial services for narco-traffickers, insurgents, and criminals through an array of front companies in Afghanistan and the UAE (United Arab Emirates.)"

While the US Treasury Department and Drug Enforcement Administration on Friday steered clear of linking the group to insurgents or political officials, they detailed the exchange's allegedly extensive role in the drug trade.

The group -- with affiliates in Dubai -- is accused of laundering cash for the Haji Azizullah Alizai cartel, "a major heroin trafficker and supplier in Southwest Asia and the Middle East."

It is also accused of using the affiliates and cash couriers to launder cash for the Haji Juma Khan Organization, which is thought to traffic opium, morphine, and heroin from the border regions of Iran, Pakistan and Afghanistan.

The sanctions also hit the exchange's founder Haji Abdullah Barakzai Ansari and a handful of managers.

The Dubai affiliates were named as Green Leaf General Trading LLC and Al Adal Exchange.

Any assets the individuals or firms have in the United States will now be frozen and US citizens are banned from doing business with it.

"Today's designation is another important step in our ongoing efforts to target money laundering and narcotics trafficking activity in Afghanistan," said US sanctions czar Stuart Levey.

Under the US Kingpin Act, offenders can face civil penalties of up to $1.1 million per violation.

For criminal violations, company executives face up to 30 years in prison and fines up to $5 million, in addition to criminal fines.

The US has recently turned its attention to money exchange houses, which are common all over the Middle East and western Asia, as it tries to crack down on insurgent groups and other illicit activities.