The city-wide strike, which began last Saturday amid Carnival celebrations, quickly led to large piles of garbage on sidewalks, sparking protests of residents.

　　The workers went on strike to demand pay increase, and they won a 9-percent hike earlier this week, according to the city sanitation company Comlurb.

　　"In our opinion, this strike is over. What we are seeing are groups of non-conformists," said Vinicius Roriz, head of Comlurb.

　　Earlier in the week, Comlurb planned to fire 300 striking workers, but revoked the decision Thursday after some sanitation workers returned to work.

　　Some workers reportedly received police escorts during their rounds as they had been threatened by strikers.

　　Trash continues to pile up in several neighborhoods, as no garbage trucks are seen shuttling. A cold front has brought rain to the flood-prone area, posing a great challenge to the city's garbage-blocked drainage system.

　　The cost of cleaning the streets in Rio, which is notorious for littering, reaches 600 million reais (250 million U.S. dollars) every year, according to the city government. Fines for randomly dumping garbage were imposed in April 2013.