DUSHANBE -- The Facebook social network and RFE/RL's website in Tajik are inaccessible in Tajikistan again.
Asomuddin Atoev, the chairman of Tajikistan's Association of Internet Service Providers, told RFE/RL that Tajikistan's leading Internet service providers received SMS instructions from the government's Communications Service requesting the sites be blocked.
However, the service's chief, Beg Zuhurov, told RFE/RL that his service had not given any instructions to block the sites.
Zuhurov suggested that the issue might have been caused by technical problems faced by the providers themselves.
Facebook and RFE/RL's Tajik site are available via a limited number of providers, but only those that are not members of the Association of Internet Service Providers.
Tajik authorities blocked Facebook and several online news sites in March and November 2012. The sites were later unblocked.