Activists say South Sudanese authorities have arrested a prominent journalist over an article he wrote supporting calls for the United Nations to send more peacekeepers to the country to protect civilians.

The East and Horn of Africa Human Rights Defenders Project accused National Security Service agents of arresting Alfred Taban, the editor-in-chief of the Juba Monitor newspaper, on Saturday afternoon and taking him to an unknown location.

Edmund Yakani, executive director of the Juba-based Community Empowerment for Progress Organization, which monitors harassment of journalists in South Sudan, confirmed the arrest. It was not immediately possible to get a comment from the government.

The call for more peacekeepers follows heavy clashes in which government troops forced the armed opposition from Juba and allegedly bombed civilians sheltering in a U.N. base.