Ukraine's security service on Friday said it had foiled a plot to murder the war-torn country's interior minister and several members of parliament.
Interior Minister Arsen Avakov has been an outspoken critic of Russia and faces prosecution in Moscow for his tough approach to pro-Moscow fighters in the east of the ex-Soviet republic.
The Security Service of Ukraine (SBU) said it had uncovered a plot to "murder the interior minister and conduct several other assassinations in Kiev and Kharkiv".
The eastern Kharkiv region's industrial heartland has narrowly avoided being swept up in a 17-month separatist uprising that has claimed nearly 8,000 lives.
"As a result of a raid, police uncovered a group that was preparing the murder of senior police officers, deputies, volunteers and businessmen," an SBU statement said.
One the gang's alleged leaders had been arrested in Kharkiv, it said, adding that the man had previously served as head of an interior ministry unit set up to thwart separatist attacks.
Avakov made no immediate comment on the alleged plot and the ministry gave out no further details.
The 51-year-old minister recently angered far-right nationalists accused of involvement in a grenade attack outside Kiev's parliament last month which killed three Ukrainian servicemen.
Avakov vowed to prosecute and seek extended jail terms for culprits, saying they bore "political, criminal and all other responsibility" for the violence.
The attack took place during protests which erupted after lawmakers gave initial backing to a bill awarding separatist regions partial self-rule -- a key part of a ceasefire agreement signed by the warring sides in February.