MANAGUA, Nicaragua (AP) — A Nicaraguan human rights group says two activists were forced off a plane for questioning by government officials in Managua amid rising tensions and detentions of dozens of anti-government protesters.

The non-governmental Nicaraguan Center for Human Rights said Sunday that indigenous rights advocate Lottie Cunningham was later allowed to board her flight out of the country but activist Haydee Castillo was taken to El Chipote prison for unknown reasons.

The detentions came just hours after police arrested 38 people at an anti-government protest that was broken up with tear gas. The government prohibited opposition protests several weeks ago.

More than 300 people have been killed since protests erupted in April calling for the resignation of President Daniel Ortega. Ortega said Saturday that those who continue to protest are "blood-thirsty."