Police have arrested 22 international activists who tried to mark the anniversary of a deadly shooting in disputed diamond fields in Zimbabwe.

The activists, who come from Brazil, South Africa, Swaziland, Kenya and Uganda, were arrested on Friday and released on Saturday, their lawyer Passmore Nyakureba told local newspaper on Saturday. They were all fined100 dollars after pleading guilty.

Two Zimbabwean activists were also arrested along with them, said Nyakureba.

“They were charged with entering a protected area without permits when they attended a workshop in Chiadzwa, Marange,” Nyakureba said.

The workshop was organized by a local non-governmental organization, the People’s Dialogue, to explore issues around informal mining in Zimbabwe.

Nine years ago Zimbabwean soldiers killed 200 people when the government took over the diamond fields and drove out informal miners.

Zimbabwe has seen an increase in arrests as the country nears the 2018 election.

On Friday, four people were arrested for booing First Lady Grace Mugabe while she was addressing a political rally. Theywere released on 50-dollar bail.

United States citizen Martha O’Donovan was arrested for allegedly calling President Robert Mugabe “a goblin” in a tweet.

The 25-year-old has been released on 1,000-dollar bail but faces up to 20 years in jail if convicted.