Authorities in Tajikistan say armed groups led by a disaffected deputy defense minister have mounted attacks that have left at least eight police officers and nine combatants dead.
An armed group killed four police in a morning shootout in the provincial town of Vahdat after another four officers were killed on the outskirts of the capital Dushanbe.
In contrast with neighboring Afghanistan, the former Soviet Central Asian nation of Tajikistan rarely sees such bloodshed and the unrest is likely to unnerve the government.
The U.S. Embassy in Dushanbe said the significance of the clashes was unclear, but "they may be precursors to other acts of violence." The embassy closed down and advised embassy staff not to go out or send their children to school.
Gen. Abduhalim Nazarzoda, the deputy defense minister accused of plotting the unrest, earned his position in government as a result of the peace deal that brought an end to the civil war in the 1990s.
Efforts to squeeze out the opposition have intensified in recent years, and Nazarzoda and other alleged accomplices in Friday's attacks are being linked with the Islamic Revival Party, which was banned by Justice Ministry decree late last month. The party denied any link to the suspects.
Internet users in the country have reported blocks on Facebook, YouTube and Russian social media service Odnoklassniki.
The crackdown against the party, the only legal Islamic political entity across former Soviet Central Asia, is likely to intensify following the unrest. The party lost its only two seats in parliament in an election this year that international observers decried as falling short of democratic standards.
Tensions provoked by attempts to stamp out all manifestations of devout Islam have bubbled under the surface. Young men are said to be pressured not have beards and official state media have mounted campaigns against women wearing veils.
The main clash took place before dawn in the town of Vakhdat, just east of the capital. The trouble was linked by local media to the fatal beating of a young man, whose relatives accused police of being responsible and said he was targeted for detention because he wore a beard.