SAO PAULO, Brazil - Sao Paulo's Public Safety Department says that at least 140 people have been slain in South America's biggest city over the past two weeks in a rising wave of violence.

Killings sharply increased in September, a month in which 144 people were killed.

A Public Safety Department official says the killings have been ordered by imprisoned leaders of an organized crime group called the First Capital Command in reprisal against crackdowns on the drug trade. He spoke on condition of anonymity Saturday because he was not authorized to speak to the press.

The department's website says 982 homicides took place in Sao Paulo between through the first nine months of the year. The victims included 90 police officers, most of them gunned down while off duty.