Hundreds of people protested in several towns across Iraq's Sulaimaniyah province on Wednesday, local sources told AFP, as rights organisations slammed the Kurdish authorities' targeting of peaceful demonstrators.

Protests against the Kurdish regional government (KRG) and the region's main parties broke out last week over a major fiscal crisis that has caused delayed public sector salaries and pay cuts.

After a tense morning across Sulaimaniyah province, there were protests in Dukkan, Rania, Darbandikhan, Piramagrun and Chamchamal on Wednesday evening, local residents told AFP.

In Chamchamal, around 300 young men gathered outside the local headquarters of the Kurdistan Democratic Party (KDP), the rival Patriotic Union of Kurdistan (PUK) and smaller parties, according to journalist Latif Fateh Faraj.

"The security forces there fired on the crowd and began chasing the protesters," Faraj said, adding that armed military vehicles were also deployed.

Kurdish tribal chiefs in the towns were working to calm the situation, residents said, with rallies dying down slightly in Piramagrun as the night wore on.

The new protests came after violence at rallies across the Kurdish region this week killed at least six people and wounded dozens, according to local officials, medics and the Iraqi Human Rights Commission.

Demonstrators in half a dozen towns had been met with gunfire as they rallied outside local government offices and headquarters of various parties.

The bloodshed prompted condemnation from the United Nations' Iraq office, which on Tuesday urged swift investigations into the deaths.

A group of human rights organisations including Amnesty International ramped up the pressure on Wednesday, accusing the KRG of "targeting civil society activists by arresting them for their work and curtailing public freedoms, including media freedom and freedom of peaceful assembly."

Prime Minister Masrour Barzani, who is also a leading member of the KDP, said on Wednesday the right to protest peacefully was "vital".

"But the violence in recent days is unacceptable," he added.

It was not immediately clear if he was referring to the security forces' response or protesters' attempts to burn party offices in several towns.

KRG authorities have tightened security measures across Sulaimaniyah province, and on Wednesday the provincial security committee said all further protests would require authorisation.

"From now on, security forces should not allow unlicensed protests, which lead to violence and chaos," the committee said.

The announcement came after KRG authorities declared a 24-hour ban on travel between towns in Sulaimaniyah province until midnight on Wednesday.

Iraq's Kurdish authorities, specifically the ruling Barzani clan, have long been accused of corruption and embezzlement of state resources.

The spontaneous protests echo similar rallies that erupted in October last year in Baghdad and Shiite-majority areas of Iraq but not in predominantly Kurdish or Sunni regions.