(CNN) Nicaraguan President Daniel Ortega describes the deadly protests raging in his country as "terrorism" and is rejecting calls to step down to defuse the clashes.

Speaking exclusively with Fox News' Bret Baier on Monday, Ortega blamed the violence on paramilitary groups funded by drug trafficking, opposition groups and even the US. He said they are attacking police, his government and loyal Sandinista families.

Ortega added that there has been a "campaign of lies, terrible lies, to try to hurt the image of Nicaragua and of its government."

Human rights groups say that at least 286 people have died since the unrest began in mid-April, when the government announced controversial changes to the social security system, kicking off the largest street protests Nicaragua has seen since its civil war ended in 1990.

The government's heavy-handed response to demonstrations ignited a national movement demanding the President's resignation.

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