Tehran, Jan 3 (IANS): The Iranian government has clamped a nationwide block on the country's most popular encrypted messaging platform Telegram after days of anti-government unrest.

"The Iranian government also requested suspension for a number of other channels that had not violated the policy on violence. When Telegram refused, the government placed a nationwide block on the app," Pavel Durov, founder of Telegram, was quoted as saying by The Verge.

Iran state TV announced that Telegram was suspended to "preserve the peace and security of citizens", according to BuzzFeed.

Internet access has been sporadically cut off to several cities where anti-government protests have taken place, and access to other social media platforms like Facebook-owned Instagram has also been intermittent.

Meanwhile, officials say that over 20 people have been killed and hundreds arrested in Iran since the protests broke out on Thursday in the northeastern city of Mashhad and spread to the capital Tehran and several other provinces.

The unrest was ignited by frustration at Iran's sluggish economy but has widened to include open defiance of Iran's ruling clergy.

Even before the protests began, Iran's government blocked popular social media platforms like Facebook, YouTube and any VPN services that might be used to circumvent the block.