DUSHANBE -- The Uzbek government has closed all border checkpoints with Tajikistan without any explanation.
A Tajik government official told RFE/RL's Tajik Service that it was not informed by Uzbek officials about the closure, which began on November 27.
Some analysts say the border is being closed ahead of Uzbekistan's Constitution Day on December 8.
Tashkent has in the past closed its border checkpoints with neighboring countries on the eve of official holidays, such as Independence Day, or a presidential election.
Uzbekistan introduced a visa regime with Tajikistan in 2001 that made travel between the two countries more difficult. There have not been any flight connections between Uzbekistan for several years.
Ethnic Tajiks are estimated to make up between 5 and 10 percent of the population of Uzbekistan.