The Russian military intelligence service GRU is not as famous as other Russian government agencies, like the KGB or the FSB.

But the GRU has been getting more attention as other countries accuse it of launching secretive and deadly operations.

The latest accusation came earlier this month from Britain, when the government identified two Russian men as GRU agents. It blamed them for nerve-agent poisonings earlier this year in Salisbury, England.

FILE - A man walks past the building of the headquarters of the Russian General Staff's Main Intelligence Department (GRU) in Moscow, Dec. 30, 2016. (AFP PHOTO / Natalia KOLESNIKOVA)

The agency

The official name of the military intelligence service is the Main Directorate of the General Staff of the Armed Forces. However, the agency is usually known by its former acronym.

The GRU is the most secret of Russia's secret services. When its former director Igor Sergun died in 2016, the official announcement was so short that it failed to give the date, place or cause of death.

The agency appears to have many responsibilities. The Russian Defense Ministry website says its job is to aid with the success of the Russian Federation by giving the government the intelligence it needs to make decisions in "the political, economic, defense, scientific, technical and environmental areas."

Allegations

Britain claims that two GRU operatives carried out the nerve-agent attack in Salisbury on former GRU officer Sergei Skripal and his daughter. Both survived the poisoning.

Three months later, two people who lived nearby became sick from the nerve agent. One died.

Investigators believe they found the container the carried the poison used in Skripal's attack.

The claim came less than two months after the United States announced charges against 12 suspected GRU agents. They were accused of hacking into the election campaign of presidential candidate Hillary Clinton and the Democratic Party in 2016.

U.S. officials say the GRU released tens of thousands of private communications as part of the Russian plan to interfere in the 2016 elections.

This year, the investigative group Bellingcat reported that a GRU officer was responsible for operations in eastern Ukraine in July 2014. At that time, Russia-supported separatist forces that were fighting Ukrainian forces. Two-hundred-ninety-eight people were killed when a Malaysian passenger airplane flying over the area was shot down.

International investigators say the plane was shot down by a mobile missile launcher brought in from Russia. The GRU officer named by Bellingcat reportedly was responsible for moving weapons to Ukraine.

Russia's RBC news service also reported this year that the GRU directs Russian citizens fighting in Syria.

Russian officials usually deny accusations against the GRU and refuse to discuss its activities. They said they did not recognize the suspects named in the Salisbury poisoning.

Other agencies

The GRU is part of Russia's large security and intelligence system, which includes the Foreign Intelligence Service, known as the SVR. It also includes the Federal Security Service, or FSB, which gathers intelligence both in Russia and overseas.

The SVR and FSB were once part of the KGB. After the collapse of the Soviet Union, they became their own organizations. Russian President Vladimir Putin, a former KGB agent, led the FSB before becoming president.

As head of state, Putin names the top leadership of the GRU. For most Russians, however, the FSB is the frightening organization because it looks for threats inside Russia. But the GRU, created under Soviet founder Vladimir Lenin, has an even harder reputation, because it looks at foreign threats.

The two agencies' operations seem to both compete and cooperate.

Pavel Felgenhauer, an independent military expert, told The Associated Press that the SVR stays away from military intelligence, and the GRU stays away from political intelligence. He said that if both sides keep this divide, they do not have to share information.

In the case of U.S. election-related hacking, Felgenhauer said, he believes the services worked together.

The Associated Press reported this story. Susan Shand adapted it for Learning English. George Grow was the editor.

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