In November an operation was carried out to exchange the soldiers of the ‘Zenith’ unit with specially trained border guards. A motorized company of border troops consisting of 208 combat soldiers, armed helicopters, 25 armored personnel carriers, 15 armored carriers, ten hand-held and four mounted grenade throwers were also secretly sent in. On 7 December two specialists from the Chief Directorate of Border Guards arrived to study the communication lines of Amin’s new residence. On 8 December the Residency was instructed to organize with precaution, the monitoring in Kabul and the provinces of ‘Buran’ broadcasts from Dushanbe beamed towards Afghanistan, and “to give your opinion of its possible use in the measures known to you.” Preparation for Operation ‘Agat’ went ahead at full speed.
The 8th Department of Directorate S of the FCD was asked to carry it out. Preparations were at the final stage. Colonel Lazarenko, the deputy head of the 8th Department of Directorate S was directly in charge. Major-General Kirpichenko, the head of Directorate S, and his deputy, Major General Krasovsky, the head of the 8th Department of Directorate S, were sent to Kabul to help Ivanov. On 12 December A.V. Petrov, the senior assistant of the 8th Department of the FCD, B.G.Chicherin, a senior operational officer, and members of other KGB directorates at the Center and the periphery flew to Kabul. On the same day ten members of Group A of the 7th Directorate of the KGB arrived in Kabul. They were joined on December 23 by another three and later by a whole group led by the head of the 7th Directorate, Lieutenant-General A.D. Beschastnov.
On 27 December the KGB began Operation ‘Agat’ [Agate] to storm the residence of the President of the DRA and the General Secretary of the Central Committee of the PDPA, H. Amin, to eliminate him and those close to him physically, to arrest his retinue and the government. Over 700 members of the KGB from the Center and the Periphery were dropped into Kabul to take part in “Operation Agat.” The troops were dressed in Afghan army uniforms. An explosion under a tree in the central square of the capital, where the explosive device had been placed beforehand, was the signal for the attack to begin. Over 100 of the KGB were killed in the attack on the palace. Such large losses forced Andropov to question the expediency of hanging portraits in mourning frames of heroes killed whilst carrying out their noble international mission in the halls and corridors as this would attract unnecessary attention.
At 10:30 a.m. on 28 December the last pocket of resistance was crushed. The house of the commander of the People's Guard, Jandad, which was not far from Amin’s residence, was seized. Jandad was captured and taken to the building of the special services. Amin’s elder brother, Abdullah, was captured in the village of Mazar-I Sharif and put in a special 'isolator' prison. Members of the government and the Revolutionary Council were arrested. Members of H. Amin’s family, his son, three daughters, daughter-in-law, the wife of the eldest son Abdurakhman and the wives of Asadullah Amin were put in Pol-I Charki prison. Two of Amin’s sons had been killed in the fighting. The arrested members of the government and the Revolutionary Council were taken to this same prison from the radio building.
Members of the KGB were promoted and received awards for “Operation ‘Agat’ [Agate].” Lazarenko was given the title of General although there was no provision for this in the establishment; Kirpichenko became Lieutenant-General and was soon appointed First Deputy Chief of the FCD; and Kozlov, a member of the 8th Department of Directorate S, was made a Hero of the Soviet Union.
Afghan officials had no idea what was happening on the night of 27 to 28 December. Minister of Communications M. Zarif, Minister of Higher and Secondary Education M. Suma, Minister of Water Resources and Energy M. Hashemi, the head of the Secretariat of the Central Committee of the PDPA Khuma, and the Consul of the DRA in Quetta, Abdul Wahed, were all in house number 104 in the 3rd district of Kabul. Some of them thought that what was happening was 'a provocation by the USA', others that it was an attack by the Muslim Brothers. To the suggestion that it could be the work of the Parchamists, Zafir replied confidently: “They won't get anywhere. The Soviets wouldn't allow it.”