Iran has lifted restrictions on the messaging app Telegram, the state news agency IRNA reported on January 13.
The popular service had been blocked during recent public protests, the most serious nationwide unrest in the Islamic republic since 2009.
"An informed source announced that the filtering of the Telegram messenger has been ended and it is being used by users," IRNA reported.
The AP news agency said it had spoken with residents in several cities, including Shiraz, Isfahan, Bandar Abbas, Rasht, and Oromieh, all of whom confirmed that they had access to the app.
Earlier this month, Iran shut down Telegram and the picture-sharing app Instagram, claiming protesters were using them to spread unrest.
At least 22 people were killed and 1,000 people arrested in the antigovernment protests that began in late December, sparked at first over rising consumer prices.
As the protests subsided, Tehran last week lifted restrictions on Instagram.
Many Iranians access Telegram using virtual private networks and other tools to bypass government filtering of the Internet, residents said.
But officials said hundreds of companies using the app for their marketing and sales had been hard-hit by the social-media restrictions, and President Hassan Rohani was quoted as saying about 100,000 people had lost their jobs.
Iran continues to impose restrictions on the Internet and social media, with Facebook and Twitter still blocked.