About 20 Tajik-Americans picketed Dushanbe's embassy in Washington on July 26, calling for peace in Gorno-Badakhshan Province.
The protesters also demanded an international inquiry into the recent violence and restored lines of communication with the region.
Government forces this week launched an operation in the autonomous eastern province against "militants" following the assassination of a high-level security official there on July 21.
Hostilities have killed around 70 people, including dozens of civilians, according to RFE/RL's Tajik Service.
The protesters in Washington chanted, "We want peace."
One protester, Sitora Djonmamadova, said she had been trying since July 24 to contact a sick relative in the region without success.
"Because of how the military operation has been carried out, we are left wondering about the safety of our family and friends," she told RFE/RL.