Facebook(FB) may have recently brought in a ban on gun sales, but it seems terrorists still use the social network to acquire weapons.
A New York Times report suggested “online bazaars” have been set up to serve people in countries where ISIS has a strong presence, such as Syria, Iraq, Yemen and Libya.
These marketplaces involved secret or closed Facebook groups, selling everything from heavy machine guns to heat-seeking missiles and anti-aircraft systems, although most of the weapons for sale were smaller handguns and rifles.
Get Data Sheet, Fortune’s technology newsletter.
The newspaper told Facebook about seven such groups, of which it promptly closed down six (the seventh apparently only discussed weapons rather than selling them). The social network noted that it relies on people to report activities that contravene its terms of service.
“It’s against Facebook’s Community Standards to coordinate private sales of firearms, and we remove any such content as soon as we become aware of it,” Facebook said in a statement. “We encourage people to use the reporting links found across our site so that our team of experts can review content swiftly.”
Awkwardly, many of the weapons being sold in Iraq appeared to have been supplied to government forces by the Pentagon.