By Steve Rosenberg
BBC News, Moscow
A series of explosions and killings in the volatile North Caucasus region in southern Russia is raising fears that the conflict in Chechnya is spreading.
Police have been frequent targets
Over the last 24 hours, there have been attacks across the region.
In Ingushetia on Friday there were three explosions, one near a courthouse, another targeted a police patrol. There were no casualties.
In the neighbouring republic of North Ossetia, a blast derailed part of a cargo train.
The attack caused major disruption.
Just hours before, a policeman was shot dead in Dagestan.
Dozens of police officers there have been killed this year and add to that the continuing bloodshed in Chechnya itself.
Early this week, eight security troops were reported to have been killed in rebel attacks.
The Russian authorities maintain that with the help of its pro-Moscow government, Chechnya is slowly returning to normal.
But there is little sign of stability there or in other parts of this volatile region.