A suicide bomber blew himself up at a police station in northern Tajikistan on Friday, killing at least one person and wounding 20, a police source said.
"There were people in the building and it's now burning," the source, who spoke on condition of anonymity, told Reuters.
He said the death toll was likely to rise but that it was not immediately clear if the dead included the suicide bomber.
The attack occurred in Khujand, about 340 km (211 miles) north of the capital Dushanbe and near the border with Uzbekistan.
Tajikistan, which has a porous 1,340-km (832 miles) border with Afghanistan, has jailed 115 people this year on charges of belonging to banned groups.