How Mafia bosses and cocaine cartels slipped on 'Green Ice': One of the greatest crackdowns on drug trafficking in the history of international crime began when two gentlemen had their tea interrupted, Patricia Clough writes from Rome

TWO South American gentlemen taking tea in a smart cafe on Rome's Piazza di Spagna are joined by strangers who tell them discreetly, but with steely firmness, to come along quietly. Thus, unnoticed by fellow customers, waiters, and - most important - fellow culprits, began one of the biggest round- ups of international drug traffickers and money launderers the world has seen.

One of the South Americans whose tea was interrupted on Friday was Jose 'Tony the Poke' Duran, 38, described by Italy's top Mafia and drugs fighters as 'the biggest distributor in the world of cocaine for the Colombian drug cartels'. It was not known, however, if Duran was his real name, as his fingerprints had been identified in various countries under more than 20 different names.

Mr Duran was described as the head of the Pereira cartel, the newest and most violent of the Colombian gangs, and was believed to act also as the main international distributor for the Medellin and Cali cartels. The man arrested with him was Pedro Felipe Villaquiran, whom Mr Duran had brought to Italy to introduce to the Mafia as his agent for Europe.

Between last Friday and last night, 201 people were arrested in four countries on two continents as Italian and US authorities, working together on 'Operation Green Ice', decapitated the most violent Colombian cocaine gang; threw a suspicious light on prominent Colombian banking, political and military figures; called in accomplices from the three most dangerous and powerful Mafia families; and seized millions of pounds in cash, jewels and property. They found more than 700kg of drugs and closed 15 companies used as fronts for trafficking.

The arrests were the result of nine months' joint work by the DEA (the American Drug Enforcement Agency) and the Central Operational Service of the Italian police after they discovered they were both probing the same connection between exports of drugs from South America to Italy and Western Europe, and the flow of laundered money in the other direction.

'Never has the Mafia suffered a blow on such a scale,' said Vincenzo Parisi, chief of the Italian police. 'We have hit the biggest organisation of cocaine trafficking and money laundering,' said Nicola Mancino, the Interior Minister. But he and others stressed that this was only the beginning and more arrests were doubtless to come.

About pounds 27m was seized in New York bank accounts belonging to what the Italian officials described as 'political and military figures in Colombia'. Two alleged lawyers for the ring were arrested at the airport of San Jose in Costa Rica.

Among the 34 people arrested in Italy were important members of the Corleone gang - one of the most powerful families in the Sicilian Mafia - as well as members of the Calabrian 'Ndrangheta and the Alfieri family from the Naples Camorra. Four people arrested in Palermo are alleged to have smuggled huge quantitites of drugs into Italy disguised as frozen fish.

Earlier this year, police tracked and filmed the arrival of 300kg of cocaine by this route. The Italian arrests also included a female employee of a large bank and the 80-year-old aunt of the head of a big New York corporation, both suspected of money laundering.