Ukraine has detained a young Russian activist on suspicion of organising sabotage during pro-Kremlin protests in which she is alleged to have shot and wounded several people.
Ukraine's SBU security service said on Wednesday that Maria Koleda, 22, had been arrested in southern Ukraine "while carrying out a mission from the [Russian] secret services to destabilise the situation".
When arrested, Koleda was carrying written instructions on how to train sabotage groups, as well as a non-lethal pistol that had been adapted to fire live ammunition, the SBU said.
Local media reported that several people were shot during clashes on Monday outside government offices in the southern city of Mykolayiv between pro-Russians and supporters of the new authorities in Kiev.
During the incident, Koleda "used firearms and in her own words wounded three", the security service said.
The USB went on to say that Koleda had told her Russian "spymaster" that her fighters had an "unlimited supply" of home-made explosives.
The USB said Koleda was sending a 13-person sabotage team to the eastern city of Donetsk, where pro-Kremlin protesters took over government offices over the weekend and declared independence.
Russian media reported that she had switched sides from a radical opposition group to supporting Kremlin policies.
Koleda can be seen posing in khaki clothes with an army-issue sniper's rifle on her VKontakte social-networking page, her red hair in a pony tail.
Anastasiya Udaltsova, the wife of radical opposition leader Sergei Udaltsov, questioned Koleda's mental health, writing on Twitter that she "has been crazy in the head since she was about 15".
The news website Slon.ru reported that Koleda had been a member of radical groups Other Russia and the Avant Garde of Red Youth before switching to a pro-Kremlin group known as Young Russia.
Koleda wrote on her social-networking page that she graduated from a Moscow university last year after studying gender politics and juvenile law.
In her last post on VKontakte, written in the early hours of Wednesday, Koleda wrote a message to pro-Russian protesters: "Don't despair ... everything is ahead."