An official at the Afghan Telecommunications Regulatory Authority, ATRA, told VOA the social media tools will be suspended for 20 days. The decision follows a request from state security institutions.
The official, who spoke on condition of anonymity, said a formal announcement is expected Saturday.
ATRA has ordered telecom companies to shut down the services November 1, according to a copy of official instructions appearing in Afghan media.
Social media users have complained of technical problems while using the two services in recent days.
The controversial move has sparked criticism of the Afghan government, and it is being slammed as an illegal act and an attack on freedom of expression.
The outage prompted the telecom regulator to issue a statement Friday, saying the ban is meant to test "a new kind of technology" in the wake of users' complaints.
It went on to defend the restriction, saying WhatsApp and Telegram are merely voice and messaging services and their temporary suspension does not violate the civil rights of Afghans. The government is committed to freedom of expression, the ministry added.
Afghan journalists and activists on Twitter dismissed the statement.
"This seems to be the beginning of government censorship. If it's not resisted soon the gov't will block FB & twitter," wrote Habib Khan Totakhil on Twitter.
"Gov't fails to deliver security, now it seeks to hide its incompetence by imposing ban on messaging platforms. Totalitarianism?," said the Afghan journalist.
"#Censorship is against what freedom we stood for in #Afghanistan post 2001. Gains shouldn't go to waste," tweeted activist Nasrat Khalid.
An estimated 6 million people in war-torn Afghanistan can access internet-based services. The growth of media and social media activism have been among the few success stories Afghanistan has seen in the post-Taliban era.
The restrictions on social media come as the Taliban intensifies attacks on Afghan security forces, inflicting heavy casualties.
The insurgent group also relies heavily on WhatsApp, Telegram, Twitter and Facebook to publicize its battlefield gains.
The Afghan government has lately barred the United States military from releasing casualty numbers, force strength, operation readiness, attrition figures and performance assessments of the Afghan National Defense and Security Forces.
The U.S. Special Inspector General for Afghanistan Reconstruction, John Sopko, while briefing members of Congress on Wednesday, severely criticized the classification move. He maintained American taxpayers have a right to know how their money is being spent.
"The Taliban know this [Afghan casualties], they know who was killed. They know all about that. The Afghans know about it, the U.S. military knows about it. The only people who wouldn't know are the [American] people who are paying for it," Sopko noted.
The United States has spent nearly $120 billion on reconstruction programs in Afghanistan since 2002. More than 60 percent of the money has been used to build Afghan security forces.