For the fifth time since the Western Australian premier, Colin Barnett, announced that many of the state’s 274 remote Aboriginal communities would be closed, protesters will shut down major cities during peak hour on Friday.

Barnett has not provided details about how many or which communities will be affected, saying only there would be “significantly fewer” at the end of the reform process.

In protest, activist group Warriors of the Aboriginal Resistance has held frequent rallies around the country, with the last round of protests held on 1 May in more than 90 locations.

Friday’s protests will focus on Melbourne and Brisbane.

The Melbourne rally will begin at 3pm, with police warning commuters to expect delays getting home as protesters move along Flinders, Swanston, Elizabeth and Bourke streets. The Brisbane rally will begin at 4pm from King George square.

Protest organisers did not return requests from Guardian Australia for comment, but in a statement on their Facebook page said the intention was to bring cities to a standstill.

“As we prepare to shut down the CBD, we watch as state and federal governments prepare to shut down Aboriginal communities in clear defiance of well expressed will of the people,” the statement said.

“It is routine in the Australian colonial state for the government to degrade, discriminate against and disrespect Aboriginal people in an ongoing campaign of genocide designed to slowly destroy us.

“We have a right to stay on our homelands, we have a right to practise our culture and we have a responsibility to stand up for our brothers and sisters impacted [on] by racist policies.”

A small protest also took place in Darwin, with more planned for that city over the weekend.