There has been a surge in sales of Kalashnikov automatic rifles after the US banned them as part of sanctions against Russia imposed following the country's annexation of Crimea.

Kalashnikov Concerns, makers of the AK-47 automatic rifle, is one of a number of companies and individuals targetted by the sanctions.

Gun retailers in the US said that since the sanctions came into effect there has been a rise in demand for its products.

"We sell some of the Kalashnikov Concern stuff and that has been selling fast," Robert Keller, manager of K-Var Corp., a Las Vegas-based online gun distributor, told CNN.

The Obama administration imposed sanctions against a number of Russian companies and individuals following Russia's annexation of Crimea in Ukraine after the Moscow-backed Kiev government was toppled in March.

Pro-Russia militants are currently engaged in combat with Ukrainian forces in eastern Ukraine, and are believed to be responsible for downing a passenger jet with Russian supplied surface-to-air missiles on Thursday, killing all 298 passengers.

As part of the sanctions, Kalashnikov is banned from exporting the AK-47 or the more advanced AK-74 Into the US.

To own a fully automatic gun in the US a special permit is required, semi-automatic Kalashnikov's are more loosely regulated under state and local laws.

In a statement on its website, the US Department of The Treasury says that US citizens are allowed to buy, own, and use the guns as long as they were imported into the US prior to the sanctions came into force.

Customers are now rushing to buy existing US sticks before they run out.

Kalashnikov Concern said the ban was really punishing US consumers.

"The products of Kalashnikov enjoy great demand in the United States. Preorders on civilian products are three times the annual volume of deliveries. Thus, the sanctions taken against Kalashnikov go against the interests of American consumers," the company said in a statement, published on Russian newsite Pravda.

AK-47 stands for Avtomat Kalashnikov-47, a reference to the full automatic action of the military models, the name of its inventor, Mikhail Kalashnikov, and the year of its unveiling: 1947.

Cheap and durable, the Kalashnikov is believed to be the world's most popular gun, with more than 100 million produced since its invention.