Islamist rebels have said they carried out a dual car bomb attack in the Dagestan region of Russia’s North Caucasus.
Police say one explosion was followed by a second more powerful blast, designed to cause as many victims as possible among the crowd who had gathered.
The attacks in Makhachkala appear to be part of an ongoing insurgency along Russia’s southern frontier by rebels fighting for a separate Islamic state.
The bombs killed a policeman and injured dozens of officers and civilians, many of whom were taken to hospital.
The attacks took place near the interior ministry and a traffic police office.
Later, outside the city, gunmen attacked a vehicle carrying a local police chief. He was unharmed but two of his bodyguards were killed.
Amid what has been a bloody few days, four rebels were reported killed on Wednesday when the bomb they were transporting went off.