Dead fish have continued to wash up on the banks of a Rio de Janeiro lake that's slated to hold Olympic rowing competitions during the 2016 games.

Fish die-offs are a frequent occurrence in Rio's waterways, which are choked with raw sewage and garbage.

The latest incident, affecting thousands of small silvery fish called twaite shad, began several days ago at the Rodrigo de Freitas lake, where the Olympic canoeing and rowing events are to be held.

With neighbours complaining about the stench, employees of the city's waste management company are working to clear away the dead fish.

Scientists had earlier confirmed presence of bacteria resistant to antibiotics in waters where Olympic sailing event will be held [AP]

In a statement, the city's environmental secretariat said the latest incident is the result of recent rains and high sea levels, which caused the lake's water temperature to plummet. The statement stressed that twaite shad are sensitive to variations in temperature, adding that oxygen levels in the lake are normal.

Rio's water quality has become a contentious topic ahead of the 2016 Olympics.

Authorities had pledged to clean up some of the waterways including the Guanabara Bay ahead of the games but now admit those promises won't be met, sparking sailors to voice worries about possible health and safety threats posed by competing in the sewage- and garbage-filled waters.

Read: 'Worst' Rio 2016 preparations

Residents concerned about the water quality of a canal in the Rio neighborhood of Recreio staged a protest Sunday. Hundreds of demonstrators linked arms along the Canal das Taxas, which is filled with raw sewage from nearby condominiums.

The canal flows into a lagoon where the Olympic Park is being built.

Meanwhile, chaos has erupted as Brazilian police dislodged squatters from a building slated for use as a luxury hotel for the Olympics.

More than 100 squatters had agreed to leave of their own accord Tuesday. But heavily armed police stormed the building as the men, women and children were filing out. Firefighters battled two fires set by squatters as police in riot gear chased people through the streets.

The squatters invaded the building in Rio's tony Flamengo neighborhood about a week ago.

Source: Al Jazeera and agencies