Zimbabwe opposition leader Morgan Tsvangirai has slammed the arrest of Pastor Evan Mawarire, the face of Zimbabwe's #ThisFlag protest campaign, who was detained at Harare airport on 1 February as he returned to the country after several months in exile.

The 39-year-old evangelical priest emerged as leader of the #ThisFlag movement encouraging Zimbabwean citizens to protest against corruption, poverty and abuse of office by President Robert Mugabe's regime, amid fears of "economic collapse" in the nation of almost 16 million.

Accused of condoning the violent protests that rocked the nation's main cities last year, the pastor was first arrested and charged for "inciting public violence" in July 2016 before a court dropped the charges.

Historic opposition leader and President of the Movement for Democratic Change (MDC-T) party Tsvangirai condemned the arrest, saying that said Mawarire had committed no crime.

"The callous arrest in broad daylight of Pastor Evan Mawarire came as no surprise to those of us who have always known that a leopard remains faithful to its spots. This is vintage Zanu-PF (ruling party) and the message coming out of this arrest is that Zanu-PF will go for broke in the campaign ahead of the next election. The world must brace for impunity and violence against the innocent citizens of our country," Tsvangirai stated.

"What happened at the Harare International Airport yesterday must send a chilling message, particularly to those in the region and in the broader international community who thought Zanu-PF was capable of reform. There cannot be reform without reformers and this impunity is a reflection of the true character of Zanu-PF."

A day after his arrest, police on Thursday (2 February) charged Mawarire with "subverting constitutional government" between 13 July and December 2016.

In response to the charges brough against the priest, Amnesty International's deputy regional director for Southern Africa, Muleya Mwananyanda, said: "The trumped-up charge of subversion brought against Pastor Evan Mawarire is absolutely ridiculous and a total sham.

"Coming after a similar charge against him last year, it is designed to make him stop his human rights activism and to punish him for speaking out about the declining human rights situation in Zimbabwe.

Mwananyanda added: "The authorities must immediately and unconditionally release Pastor Evan Mawarire, as he is a prisoner of conscience imprisoned solely for the peaceful exercise of his rights."

Following his release in July 2016, Mawarire fled to South Africa, and the United States in fear for his life after being publicly denounced by Mugabe, whose security forces are accused of quelling dissenting voices.