The toll from protests against northern Iraq's Kurdish authorities has risen to six dead, medics and officials said Tuesday, as rage swells over delayed public sector salaries and pay cuts.

After a first protester was shot dead in the town of Chamchamal on Monday afternoon, another two demonstrators died overnight in deadly rallies in two other districts, according to a local official and the Baghdad-based Iraqi Human Rights Commission.

On Tuesday afternoon, at least three more protesters died in two other locations, local officials, medics and the Commission told AFP.