Police in Italy have arrested at least 300 suspected members of a powerful mafia in a crackdown described as the biggest in the past 15 years.

At least 3,000 officers made the arrests in the southern region of Calabria and across northern Italy, the police said on Tuesday.

The suspects were arrested on suspicion of mafia association, murder, arms offences, trafficking, extortion and other crimes.

Domenico Oppedisano, 80, who is believed to be the most senior leader of the 'Ndrangheta mafia, was also arrested, according to Italian media.

Ndrangheta targeted

Roberto Maroni, the interior minister of Italy, said the operation "struck the 'Ndrangheta at the heart of its criminal system, both in terms of organisation and in terms of finance."

Police seized assets, weapons and drugs and arrested entrepreneurs working in the health sector.

The arrests in northern Italy, aimed at the 'Ndrangheta's commercial interests, "confirm that northern Italy is the true theatre of operations for the 'Ndrangheta", Alberto Cisterna, an anti-mafia prosecutor, told AFP.

Healthcare "is the sector they prefer, since it allows them to establish contacts with politics and with public administration," Cisterna said.

The operation, the largest against the 'Ndrangheta since 1995, comes after an internal war during which the northern branches tried and failed to secede from the southern base.

In recent decades, the 'Ndrangheta has become the largest and most feared of Italy's four large organised crime syndicates, which include the Camorra in the area of Naples, Cosa Nostra in Sicily and the smaller Sacra Corona Unita in the southeastern region of Puglia.

The mafia group is also considered to be the main broker in the international cocaine traffic, with a virtual monopoly of cocaine coming from Colombia.