Soviet SA-7 SAM's (Surface-to-Air-Missiles) are being sold on the black market in Nicaragua. Senior Nicaraguan army officers may have a secret stash of 80 or more according to this Washington Times Report:
Nicaraguan police, with U.S. assistance in a sting operation, thwarted black marketeers trying to sell SA-7 shoulder-fired missiles capable of downing commercial aircraft earlier this month, raising fears that some missiles already have been sold to terrorists, The Washington Times has learned.
U.S. officials think the missiles are being provided by elements of the Nicaraguan military. One official said intelligence reports suggest Nicaraguan army elements are keeping a secret stash of SA-7's not inventoried by international inspectors...
"This is a very, very serious threat," said the U.S. official. "This is what makes me stay up at night. Civilian aviation is at stake."
The official said one Soviet-made SA-7 was confiscated at an air conditioning repair shop, the site of the sting in Managua, Nicaragua, where three Nicaraguans tried to sell the missile and offered more to undercover Nicaraguan police.
"This shows that such missiles can be bought on the open market, and it highlights the need for strong international cooperation to get rid of them,"
Nicaraguans seize missile during sting [Washington Times]
How to Avoid a Heat-Seeking Missile [Wired, March 2004]