A Moscow court on Saturday issued criminal charges against seven people "motivated by national hatred" to kill two prominent Russian journalists in a Ukrainian-backed plot, Russia's state-owned TASS news agency said.
The court approved the detention until Sept. 14, under criminal charges of "hooliganism," of five minors born in 2005 and 2006 and two men it said were part of an organized group, TASS said.
TASS said Russia's FSB security service detained an unspecified number of people on Friday who carried out reconnaissance near the homes and workplaces of journalists Margarita Simonyan and Ksenia Sobchak.
There was no immediate comment from Ukraine, which in the past has denied involvement in assassinations of pro-war figures inside Russia.
Interfax news agency quoted the FSB as saying that the detainees had admitted preparing attacks on the two women on behalf of Ukraine and had been promised a reward of 1.5 million roubles ($16,620) for each one.
Simonyan, head of state media outlet RT and a vocal supporter of Russia's war in Ukraine, posted a message on Telegram about the alleged plot, urging the security services to "Keep on working, brothers!"
Sobchak is a well known journalist and TV host who also ran as a presidential candidate in 2018.
Past attacks on journalists in Russia
Two prominent pro-war Russian figures, journalist Darya Dugina and military blogger Vladlen Tatarsky, have been killed in bomb attacks inside Russia in the past year. Russia blamed their killings on Ukraine, while Kyiv denied that and portrayed them as evidence of Russian infighting.
In May a prominent Russian nationalist writer, Zakhar Prilepin, was wounded in a car bombing that killed his driver. Investigators said a suspect had been detained and had admitted acting on behalf of Ukraine.