Iran on Thursday began restoring internet access in Tehran and some provinces after a five-day shutdown to help stifle protests against fuel price rises.
The Revolutionary Guard Corps said calm had returned across Iran, state TV reported.
Amnesty International said more than 100 demonstrators had been killed by security forces, a figure rejected as "speculative" by the government.
"The internet is being gradually restored in the country," the semi-official news agency Fars said.
The National Security Council that ordered the shutdown approved reactivating the internet in some areas, officials told Fars.
"According to reports so far, fixed line internet has been restored in Hormozgan, Kermanshah, Arak, Mashhad, Qom, Tabriz, Hamadan and Bushehr provinces, and parts of Tehran," it reported.
The internet block made it difficult for protesters to post videos on social media to generate support, or to obtain reliable reports on the extent of the unrest.
Monitor NetBlocks said restoration of connectivity covered only about 10 per cent of Iran.
News agencies and residents said fixed-line internet was partly restored, not mobile internet.
Protests began on November 15 in several provincial towns after the government announced petrol price rises of at least 50 per cent.
They spread to 100 cities and towns and quickly turned political, with protesters demanding that top officials step down.
US President Donald Trump on Thursday criticised Iran for blocking the internet.
"Iran has become so unstable that the regime has shut down their entire internet system so that the great Iranian people cannot talk about the tremendous violence taking place within the country," Mr Trump tweeted.
"They want zero transparency, thinking the world will not find out the death and tragedy that the Iranian regime is causing."
The International Monetary Fund said it regretted the violence and loss of life during the protests, and had not discussed the fuel price rise with Iran.
"In general, the IMF continues to advise oil-producing countries in the Middle East and Central Asia region to reduce fuel subsidies while compensating the poor with targeted cash transfers, which we understand is the approach Iran has taken," IMF spokeswoman Camilla Andersen said.
On Thursday, state TV showed thousands marching in pro-government rallies in a dozen cities, carrying national flags and signs with slogans including "Rioting is not protesting".
Amnesty said it had documented at least 106 protesters killed by security forces, which would make it the worst street unrest in Iran in at least a decade and possibly since the 1979 revolution.
Iran’s UN mission on Wednesday dismissed the casualty report as "speculative, not reliable".
Iranian authorities said several people, including members of the security forces and policemen, were killed in street violence, which Tehran blamed on "foreign foes".