Eyewitnesses said the explosion occurred when the man -- identified as a 77-year-old janitor -- picked up a plastic bag outside the Palace of Unity (Kokhi Vahdat), hours before it was to host an international conference. Reports say the explosion blew out many windows at the palace.
Tajik Prime Minister Oqil Oqilov was to attend the conference on dealing with the consequences of natural disasters, which was organized by the European Union. The conference was postponed until later in the day.
Speaking to reporters today, Dushanbe city prosecutor Qurbonali Muhabbatov said it is still too early to say who was behind what he called a "terrorist attack." Muhabbatov said a criminal case will be opened today and investigated by the Ministry of National Security.
The Soviet-era Palace of Unity, which hosts international conferences and meetings, is also the headquarters of Tajikistan's ruling People's Democratic Party. The Uzbek Embassy is located about 100 meters from the palace, which is also close to the Hotel Avesto, one of Dushanbe's most prestigious hotels.
Police have cordoned off the area. The Hotel Avesto has evacuated its guests -- who are mostly foreigners -- to a "safer place."
Another explosion took place in Dushanbe near the Supreme Court on June 16, but no casualties were reported.