Swedish researchers warn of Russian arms

"The remarkable increases in Russian companies' arms sales in both 2012 and 2013 are in large part due to uninterrupted investments in military procurement by the Russian government during the 2000s," said Siemon Wezeman, senior researcher at the Stockholm International Peace Research Institute (SIPRI).

Sales by Russian-based arms firms grew by 20 percent in 2013, according to SIPRI.

However, figures for the 100 biggest arms companies excluding China declined for the third year in a row, with a two-percent drop in sales in 2013 to $402 billion (322 billion euros).

SIPRI's report does not include China due to a lack of reliable data. China's companies supply a military that enjoys the world's second-biggest budget.

The Russian company with the biggest increase in sales in 2013 was Tactical Missiles Corporation, which registered a 118-percent hike, followed by Almaz-Antey, with a 34 percent increase.

Almaz-Antey is now the 12th-largest arms manufacturer in the world, getting closer to the top 10, "which has been exclusively populated by arms producers from the US or Western Europe since the end of the Cold War," SIPRI said.

The US still dominates the list with six companies in the top 10.

Russia's increasing assertiveness in neighbouring regions, including recent repeated airspace violations in the Baltic Sea has become a major concern for Sweden and other European countries.

On Friday a Russian aircraft almost collided with a Swedish passenger plane in the skies above Scandinavia.

Pro-Russian separatists in east Ukraine have been fighting Ukrainian forces since April in a war which has claimed more than 4,000 lives and driven hundreds of thousands of people from their homes. Moscow has repeatedly denied involvement but openly gives political backing to the self-declared separatist statelets in the east.

Stockholm-based think-tank SIPRI was created in 1966 and is partly financed by the Swedish state. It specialises in research on conflicts, weapons, arms control and disarmament.

The think-tank defines arms sales as "sales of military goods and services to military customers including both sales for domestic procurement and sales for export."