Security services in Ukraine say they have uncovered a plot to kill Russian prime minister Vladimir Putin and have detained two men in the port of Odessa.
The report comes less a week before the Russian presidential election, which Mr Putin is widely expected to win.
The two men were shown on Russian TV admitting their involvement in the plot.
One of the men said he had been hired by Chechen militant leader Doku Umarov to carry out the killing.
The other man has reportedly been on an international wanted list since 2007.
The plotters were said to be planning to plant mines on a Moscow street that is used by Mr Putin on a daily basis.
The alleged assassination attempt against Mr Putin is at least the sixth reported by the Russian media since he first became president 12 years ago, AFP reports.
The last was reportedly planned for his June 2007 visit to Istanbul for a regional summit.