The United Nations voiced alarm Tuesday at reports dozens may have been killed in Iranian demonstrations, as the Islamic republic said it would unblock the internet only once calm has been restored.

Amnesty International said more than 100 demonstrators were believed to have been killed across Iran in five days since security forces were ordered to "crush" the protests triggered by fuel price rises.

Iran's economy has been battered since May last year when the United States unilaterally withdrew from a 2015 nuclear agreement and reimposed crippling sanctions.

Copyright Agence France-Presse, 2019