The United States has sanctioned Tanzania’s police chief and barred him from entering the US, citing alleged human rights violations committed by the police force.

The sanctions announced Thursday followed a general election in October in which President Samia Suluhu Hassan won a full term with 97% of the vote after a crackdown on opposition figures.

US Secretary of State Marco Rubio said in December said the country was reviewing its ties with Tanzania over repression and election violence.

Rubio said the sanctions designation against police Senior Assistant Commissioner Faustine Jackson Mafwele was based on credible information he was involved in rights violations.

“One year ago, members of the (Tanzanian police) detained, tortured, and sexually assaulted Ugandan activist Agather Atuhaire and Kenyan activist Boniface Mwangi, who were in Dar es Salaam to observe the trial of opposition leader Tundu Lissu,” he said in the statement.

The Ugandan and Kenyan activists were arrested and detained in Tanzania in May last year.

They alleged that they were tortured by Mafwele while in detention before being abandoned near the Kenya–Tanzania border.

A commission Hassan appointed to investigate postelection violence found 518 people were killed and thousands were injured.

The opposition believes the casualty figures are much higher in the first major violent protests in the East African nation in decades.

The commission’s report, released in April, recommended further investigation of police conduct during the protests, during which unarmed civilians were reportedly shot in their homes.

Internet access in the country also remained disrupted for several days after the polls, and videos of the shootings were shared on social media after the restoration of internet access, despite police warning people not to share videos online.