So-called 'Operation Cronos' was conducted by some 6,500 police officers. It was carried out ahead of national elections in October. Planning for the sweep began in July.

"What matters to us is protecting lives and above all combating femicide, this terrible and unacceptable crime," said Public Security Minister Raul Jungmann. "Some crimes are more serious and repugnant, especially those against women."

A respected annual report released this month by the non-profit Brazilian Forum for Public Security found a six percent increase in the murders of women in 2017.

These included 1,133 deaths as a result of femicide, or victims being deliberately targeted because they were women. The 60,018 rapes were up more than eight percent compared to 2016.

The status of Black women in Brazil in particular came under the spotlight earlier this year after the execution-style murder of popular Rio de Janeiro city councilwoman, Marielle Franco.

An activist for human rights and women's causes, she had spoken out against the plight of the country's Black population.

According to statistics from Brazil's Institute of the Black Woman, or Institute Da Mulher Negra in Portuguese, more than 60 percent of all women killed in the country are women of color.