Police broke up an Italian-Canadian mafia clan that ran drug trafficking and money laundering operations, arresting 12 people on Tuesday and seizing millions of dollars in assets, officials said.

Police arrested 11 Italians in cities across the country and one in Cannes, France, while seven Italian-Canadians already jailed in Montreal were served additional warrants, anti-mafia police in Rome said. Police could not immediately say if those jailed in Canada were dual nationals.

The clan was led from Canada by Nick and Vito Rizzuto, a father and son, who were jailed for previous crimes respectively in 2006 and 2005, said anti-mafia official Col. Paolo La Forgia.

"From prison they pulled the strings of their Italian colonies," La Forgia said by telephone.

Among those arrested in Italy were two bank workers who managed the clan's Swiss bank accounts. Police in Italy and abroad also seized assets, property and companies worth euro150 million (US$212 million), La Forgia said.

The group's members are accused of mafia association, money laundering and other financial crimes.