The gunmen — between 1,000 and 1,500 of them, according to some estimates — are part of a recently formed paramilitary force protecting the continued rule of President Daniel Ortega against a three-month-old civilian uprising. Their main tactic is terror. They conduct roundups, fire at protesters, carry out dark-of-night raids and menace the population.

The Pro-Human Rights Association of Nicaragua said Thursday that paramilitary forces have conducted 595 "kidnappings" and disappearances of citizens since the uprising began April 18. The group said it has tallied 97 killings since July 11.

"Today in Nicaragua, there exists an undeclared state of siege," Alvaro Leiva, executive director of the rights group, said at a news conference.