An Ethiopian court has convicted an opposition politician of encouraging terrorist acts after he criticised the government’s response to protests in Facebook posts.

Rights group Amnesty International said the case of Yonatan Tesfaye, a former spokesperson for the opposition Semayawi Party who was arrested in 2015, was a miscarriage of justice.

Yonatan was charged with “encouragement of terrorism” in May 2016 in relation to comments made on the social media site in 2015 in which he said the government had used excessive force against protesters.

The charges were brought under a 2009 law that prescribes jail terms of between 10 and 20 years for anyone convicted of publishing information that could induce readers to commit acts of terrorism.

“This is not a crime, yet he now faces up to 20 years in jail under this draconian and deeply-flawed law,” Michelle Kagari, Amnesty’s Deputy Regional Director for East Africa, the Horn and the Great Lakes, said in a statement.

“This ruling is a shameful affront to people’s right to express themselves and further entrenches repression in Ethiopia.”

Yonatan will be sentenced on May 25. His lawyer Shibiru Belete told Reuters they will lodge an appeal.

Ethiopia’s 547-seat parliament does not have a single opposition politician and opposition groups accuse the government of constant harassment and intimidation.

The Horn of Africa country declared six months of emergency rule in October after more than a year of violent protests in its Oromiya and Amhara regions, where demonstrators say the government has trampled on their political rights.

The state of emergency has since been extended by four months.

(Reporting by Aaron Maasho; Editing by Elias Biryabarema and Catherine Evans)