At least six people were killed when protesters angry over what they see as unfair food aid distribution during the coronavirus pandemic clashed with police in Afghanistan's central Ghor province.

Provincial councillor Abdul Basir Qaderi said police opened fire on Saturday after demonstrators damaged government property with stones and attacked security forces.

He said warning shots and water cannon failed to disperse the protesters. The dead included two police officers, a journalist and three protesters. Those wounded included 10 police officers and nine demonstrators.

"The city is in a military situation now," Qaderi said. "There are tanks on the roads."

The Afghanistan Independent Human Rights Commission (AIHRC) is looking into the "worrying reports of police firing on protesters", its chairperson Shaharzad Akbar said on Twitter.

Rights group Amnesty International also called for an independent investigation into the use of police force.

Reacting to the incident, Afghanistan's First Vice President Amrullah Saleh said he was shocked and saddened by the news.

"We will investigate the incident seriously," Saleh wrote on Facebook.

Ghor is one of the most deprived, undeveloped and insecure provinces in the country.

Afghanistan has begun the free distribution of bread at bakeries for the poor as the coronavirus lockdown continues.

Nationwide, there have been about 4,000 confirmed cases out of 15,000 tests conducted.

The World Bank said on Friday in addition to security and political uncertainties, the global pandemic and high rate of poverty have caused major challenges in Afghanistan.