GENEVA — The Nicaraguan authorities and paramilitary groups working with them have killed, tortured, raped and forcibly disappeared anti-government protesters, creating a climate of fear that is driving thousands of people to flee the country, the United Nations said Wednesday.

“Repression and retaliation against protesters continues in Nicaragua as the world looks away,” said Zeid Ra’ad al-Hussein, the United Nations human rights chief, in a statement.

Around 300 people have died and more than 2,000 have been injured as the authorities resort to multiple forms of repression — including extrajudicial killings, widespread arbitrary detentions and the ferocious intimidation of critics — to curb protests in the past five months, according to a report released by the rights agency.

In one of his last official appearances before stepping down as high commissioner for human rights, Mr. al-Hussein called for action by the United Nations Human Rights Council and the international community to prevent the country from plunging into deeper social and political turmoil.