Rome: Italian police arrested three suspected Albanian drug traffickers and seized 170kg of heroin on Tuesday in one of the biggest anti-drug operations in recent years, officials said.

The criminal gang had allegedly been trafficking heroin from Pakistan and Afghanistan, through the Balkans and into Italy. Traffickers were taken by surprise as they were refining heroin, the police said.

Durim Vishkurti, 31 years old, Sokol Cota, 35 and Ermal Dorda, 25, were arrested in an operation launched in the provinces of Verona and Padova in an operation led by the Venice anti-mafia squad.

Investigators had put the suspected North African and Italian drug-pushers under surveillance which led them to two houses in northeast Italy, one of which acted as a laboratory.

The investigation has lasted a year and four other Albanian suspected drug traffickers had already been arrested by customs in the preceding months.