MOSCOW - Russia has foiled several assassination attempts targeting a senior defense official and a military blogger, the Russian Federal Security Service (FSB) said on Saturday.

Ukrainian intelligence services coordinated the attacks and a Russian citizen had been arrested in connection with the plots, the FSB said in a statement.

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The suspect allegedly planned to use an improvised explosive device disguised as a portable speaker, according to the statement.

Last week, a Russian lieutenant general and his assistant were killed in an explosion in a Moscow residential building.

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The FSB also revealed on Thursday that it had thwarted multiple assassination attempts orchestrated by Ukrainian special services against high-ranking Russian military officials. Four Russian citizens were arrested in connection with these plots.