A s the world demands answers after the murder of Saudi dissident and journalist Jamal Khashoggi , ET Magazine looks at some of the chilling attacks in covert operations around the world:One of the etymological origins is believed to be the Arabic word hashishin, literally, hashish users. It was used to describe Persian militants of the 4th to 16th century AD who used to consume hashish before going on their killing missions.Last week, Turkish officials alleged the hand of the Saudi Arabia government in the killing of journalist Jamal Khashoggi, a Saudi dissident and a reporter with The Washington Post. Over two weeks ago, Khashoggi entered the Saudi consulate in Istanbul to obtain documents for his upcoming wedding and never came out. The Turkish officials said he was beaten and tortured inside the Saudi consulate. Audio recordings they received as part of the investigation reportedly suggested he was beheaded and dismembered, his fingers severed.Saudi government later acknowledged that Khashoggi was killed while visiting its consulate in Istanbul, but claimed that he died in a fistfight.The Russian annals are fraught with attacks on political dissidents inside and outside the country.In a high-profile case from March, Sergei Skripal, a Russian spy-turned-double agent for the UK intelligence, was found unconscious on a park bench in Salisbury, England, along with his daughter Yulia. who had flown down from Moscow to visit her father. It was later discovered that they were poisoned with a lethal nerve agent. The two survived but the British government accused the Russian government of having a hand in the poisoning.Putin has denied all such accusations against him and the Kremlin as “ungrounded”.Between 1988 and 1998, about 100 Iranian intellectuals and activists were reportedly killed for propagating cultural and political reforms. They were killed by car crashes, stabbings, shootings, and with injection of potassium to cause heart attacks.Ayatollah Khamenei denied the hand of state in these murders. Later it, was announced that some rogue elements in the Ministry of Intelligence were behind the killings.Among the victims were a dissident couple Dariush and Parvaneh Forouhar, who were stabbed in their house in Tehran. Two decades later, their daughter Parastou Forouhar, a Germany-based artist, is fighting with the government for justice of her parents’ brutal killing. In return, the Iranian government has charged her with propaganda against the state for talking to foreign media about her parents’ death and the government’s alleged role in it.Bulgarian dissident writer Georgi Markov, killed in London, was probably the most notable Cold War casualty.Markov was a strong critic of the Bulgarian communist regime. He was allegedly killed by the Bulgarian secret police with help from Soviet security agents.One fine September morning in 1978, Markov felt a sharp pain in his leg while waiting at a bus stop at the Waterloo Bridge. He saw a man picking up an umbrella off the ground and apologising to him. It was later found that this umbrella had a poisoned tip that infected Markov and caused his death.America’s Central Intelligence Agency (CIA) has been blamed for several failed attempts on the life of the late Cuban leader Fidel Castro. One of Castro's security men said a total of 634 attempts had been made on his life. He wrote a book on it: Executive Action: 634 Ways to Kill Castro. One of the alleged plots was to give an exploding cigar to Castro when he visited the UN in New York. The Guardian says, "Another was to contaminate a cigar with botulinum toxin but it never actually reached him and he quit smoking in 1985."According to a report by The Guardian on CIA's attempts, "Earlier well-documented episodes include Congo’s first prime minister, Patrice Lumumba... judged by the US to be too close to Russia. In 1960, the CIA sent a scientist to kill him with a lethal virus, though this became unnecessary when he was removed from office... by other means."An extremely toxic nerve agent called VX was used in the alleged political assassination of Kim Jong-nam, half-brother of North Korean leader Kim Jong-un.The device of killing with a poisoned umbrella tip was recently adapted for the plot of Raazi where Alia Bhatt played an Indian spy in Pakistan.The New York Times, The Washington Post, Frontline, Business Insider, Radio Free Europe/Radio Liberty, MurderMap UK, The Guardian