Around 100 suspects have been arrested and 85 weapons seized when police conducted dozens of simultaneous raids in Buenos Aires province, Argentine authorities say.
The massive police operation in the southern edge of the capital comes amid a year-long public safety state of emergency declared this month by the governor of the province to fight a spike in violent crime and vigilante action against it.
The police operations on Saturday also netted a reported 12 cars and 29 motorcycles, police body armour and drugs, as well as shotguns matching the type carried by Argentine security forces.
Buenos Aires Province Governor Daniel Scioli, an ally of President Cristina Kirchner with aspirations to the presidency, on April 5 decreed the state of emergency in the province that is home to 40 per cent of Argentina's 40 million people.
The decree followed a series of robbery-murders that triggered a furious response from people who attempted to lynch suspected thieves.
Some of them were beaten to death in the street.
It frees up 600 million pesos ($A80.30 million) to ramp up security, including to pay for some 5000 retired police officers to beef up patrols, Scioli said.
He announced a decentralised system for emergency calls, a "panic button" app for mobile phones and measures against drug trafficking, which he blamed for the worst of the rise in crime.
