Johannesburg - The Committee to Protect Journalists has joined more than 20 rights groups in urging the Zimbabwean government to restore internet and social media services blocked during a nationwide protest against a steep fuel price increase which turned violent.

Police said three people, including a member of the force, were killed during demonstrations which saw angry protesters block roads with stones and ransack and loot shops in major cities.

In response, residents in Zimbabwe said internet services had been cut off, with only those on virtual private networks enjoying continued access.

"The government in Zimbabwe should take action to ensure a free and open media environment, which means swiftly reestablishing internet and social media access," CPJ Africa Program Coordinator Angela Quintal said.

"African governments too often use internet disruptions as a tool to stifle the free flow of news and commentary."