Internet users in Tajikistan say hundreds of websites, including Facebook and YouTube, have been inaccessible in the Central Asian country since October 5.
Asomuddin Atoev, the chairman of Tajikistan's Association of Internet Service Providers, told RFE/RL on October 6 that at least 200 websites, including popular Russian social networks, remain inaccessible.
Media reports said the outages may be linked to opposition calls on social networks for a protest in Dushanbe on October 10.
The calls have been issued by exiled opposition leader Umarali Quvatov's organization, Group 24.
The state Communications Service's deputy chief, Rafiqjon Shokirov, told RFE/RL that the service "has not given any orders to block any sites."
He said "the reports about alleged blocking of websites, including Facebook, do not correspond to reality."
Tajik authorities have been accused of blocking popular websites several times in the past two years.