Read the following paragraph and extract the answer for the question: What is the name of the force that watched the border troops to ensure they did not escape?

Following the end of the Second World War, the East German side of the border was guarded initially by the Border Troops (Pogranichnyie Voiska) of the Soviet NKVD (later the KGB). They were supplemented from 1946 by a locally recruited paramilitary force, the German Border Police (Deutsche Grenzpolizei or DGP), before the Soviets handed over full control of the border to the East Germans in 1955/56. In 1961, the DGP was converted into a military force within the National People's Army (Nationale Volksarmee, NVA). The newly renamed Border Troops of the GDR (Grenztruppen der DDR, commonly nicknamed the Grenzer) came under the NVA's Border Command or Grenzkommando. They were responsible for securing and defending the borders with West Germany, Czechoslovakia, Poland, the Baltic Sea and West Berlin. At their peak, the Grenztruppen had up to 50,000 personnel.Around half of the Grenztruppen were conscripts, a lower proportion than in other branches of the East German armed forces. Many potential recruits were screened out as potentially unreliable; for instance, actively religious individuals or those with close relatives in West Germany. They were all subjected to close scrutiny to assure their political reliability and were given intensive ideological indoctrination.A special unit of the Stasi secret police worked covertly within the Grenztruppen, posing as regular border guards, between 1968 and 1985, to weed out potential defectors. One in ten officers and one in thirty enlisted men were said to have been recruited by the Stasi as informers. The Stasi regularly interviewed and maintained files on every guard. Stasi operatives were directly responsible for some aspects of security; passport control stations at crossings were manned by Stasi officers wearing Grenztruppen uniforms.The Grenztruppen were closely watched to ensure that they could not take advantage of their inside knowledge to escape across the border. Patrols, watchtowers and observation posts were always manned by two or three guards at a time....
user
The Stasi
assistant