The Nicaraguan Foundation for Economic and Social Development, one of the country's most respected think tanks, said the country's political crisis could cause serious economic problems in the short and medium terms.

The foundation warned that if the problems continue until the end of July, Nicaragua's economy could lose $US404 million and 20,000 jobs. The rate of economic growth could also fall by 3.2 percentage points, it said.

The latest report by the non-governmental Nicaraguan Centre for Human Rights attributed more than 135 deaths to the protests and response by the government and Sandinista youth groups. The government has a lower death toll.

Protests began in mid-April in response to changes to the social security system, but expanded to call for Ortega's exit from power.

AP