Another 10 people - one of them a police officer - were killed here overnight, bringing to 83 the number of murders committed over the last 11 days in Brazil's largest city and financial capital, authorities said Friday.
Eighty-nine cops have been slain so far this year in Sao Paulo and the likenamed surrounding state.
Partly in response to the recent surge in violence, police mounted an operation this week to neutralize gangs in three of the city's "favelas," or slums.
The raids and occupations have netted 22 arrests, 15 illegal guns, 24 kilos of cocaine and 254 kilos of marijuana, police said.
In the San Remo favela police discovered a tunnel they say was being used to smuggle drugs onto the campus of the University of Sao Paulo, Brazil's leading academic institution.
The Sao Paulo state government, led by former opposition presidential candidate Geraldo Alckmin, says the recent flare-up in violence is a reaction to the success police are having against the city's criminal organizations.
Federal authorities, however, said they warned police in Sao Paulo that major criminal outfits were planning an offensive against law enforcement in the metropolitan area.
After earlier refusing an offer of help from Brasilia, Gov. Alckmin agreed Thursday in a telephone conversation with President Dilma Rousseff to accept assistance from the federal government.
The details of the assistance are to be worked out by Alckmin, police commanders and federal Justice Minister Jose Eduardo Cardozo.