This is a serious threat and yesterday's events, when the police destroyed four militants, testify to this, the law-enforcers said in a statement.
The gunmen were carrying bombs, including two bombs in cardboard boxes weighing 50 and 10 kilos. The bombs were outfitted with a detonator and stuffed with bolts and screws.
The bombs were connected to timers and could be set off any moment.
Two policemen were killed during the operation to search for and capture the group.
The Stavropol interior department urged to toughen control arrangements at life support and other crucial facilities; and to resume patrols in residential blocks and engage public organisations in patrolling.