Putin 'assassination plot': one arrested
In October, a Russian news agency reported there was a plot to kill President Putin while on a trip to Iran.
According to the reports several groups of suicide bombers had been trained to carry it out.
Despite the security fears Putin still went to Tehran to take part in a summit of five Caspian states.
Iran then dismissed the plot as groundless calling it “psychological warfare” by Tehran's enemies to undermine relations with Moscow.