According to Afghan airport officils, hewed bars of gold are being flown out of Kabul with increasing regularity, confounding Afghan and U.S. officials who fear money launderers have found a new way to spirit funds from the country

Most of the gold is being carried on commercial flights destined for Dubai, United Arab Emirates, New York Times reported.

The amounts carried by single couriers are often heavy enough that passengers flying from Kabul to the Persian Gulf emirate would be well-advised to heed warnings about the danger of bags falling from overhead compartments.

One courier, for instance, carried nearly 60 pounds of gold bars, each about the size of an iPhone, aboard a flight in mid-October, according to an airport security report. The load was worth more than $1.5 million.

This comes as a U.S. watchdog agency said Tuesday that Afghan officials were resisting U.S. efforts to help track billions of dollars being flown out of Kabul airport every year, some likely linked to crime and drugs.

The U.S. and other nations have long expressed concern about the amount of cash being flown out of the country — an estimated $4.5 billion last year, according to the U.S. Congressional Research Service. Afghanistan has a cash-based economy and moving large bundles of cash is common, yet it raises the risk of money laundering and cash smuggling to finance terrorist, narcotics and other illicit activities.

In 2010, the United States launched a program to help Afghanistan control the problem, particularly through greater controls at Kabul International Airport, and President Hamid Karzai’s government pledged action within a year.

Hundreds of millions of dollars from the collapsed Kabul Bank were flown out of Afghanistan — some in airplane food trays — to more than two dozen other countries, a recent report on the collapse said. The demise of the bank, the nation’s largest financial institution, became a symbol of endemic corruption that plagues Afghanistan.

“The persistent delays in instituting basic anti-money laundering procedures by the Afghan government at Kabul International Airport are deeply troubling,” the report by the Special Inspector General for Afghanistan Reconstruction said. “Although proper controls to monitor cash flows are important for any country to institute, they are particularly critical for a country fraught with corruption, narcotics trafficking and insurgent activity.”