At least eight people have been hurt in two separate blasts at a riot police base near Russia's rebel region of Chechnya, Russian news agencies have reported.
Interfax, quoting local police, said the first explosion, caused by a bomb, occurred outside the OMON riot police base in Makhachkala in Dagestan, neighbouring Chechnya.
The agency said the blast occurred as a bus carrying police officers arrived at the base. One of the injured was said to be a woman who was in a serious condition.
An hour later, a second explosion took place about 50 metres from the base but no one was injured in this explosion, according to preliminary information, Interfax said.
Dagestan, on the Caspian Sea, has suffered from an overspill of violence from Chechnya where separatist rebels are fighting Russian forces and has been the scene of kidnappings, killings and bomb explosions in the past five years.