Harare (AFP) - A Zimbabwean pastor who led a popular protest movement last year against strongman President Robert Mugabe said Friday that he might stand in the 2018 general election.

Evan Mawarire was publicly threatened by Mugabe, 92, after starting the "This Flag" internet campaign that triggered the largest surge of anti-government street protests in many years.

Mugabe has vowed to run again and has already been chosen as the candidate for the ruling ZANU-PF party, which has been involved in brutal violence and vote-rigging in past elections.

Mawarire, who is on bail, faces charges of subverting the government and inciting public violence after he was arrested earlier this month at Harare airport.

"If the need arises or if it becomes necessary for me to participate in the elections I really want to be available for that," he told reporters outside court on Friday.

"I believe it is my duty as a citizen to serve my nation in that way... I haven't made that decision as yet but certainly I don't want that door to be closed."

Mawarire fled the country in July in fear for his life, and was arrested on his return.

The evangelical pastor, 39, emerged as an opposition figurehead after posting a Facebook video in which he wore Zimbabwe's flag on his shoulders as he condemned the country's worsening economic crisis.

Following Mugabe's intervention, security forces crushed the series of protests and work strikes organised by the "This Flag" movement and other groups.

In the last election in 2013, Mugabe easily defeated the opposition Movement for Democratic Change in a vote widely seen as not credible.

The court case against Mawarire was postponed until March 16.