In July this year, a 17-year-old travelled 500 miles from his home in eastern Ukraine to collect a bomb and a phone hidden in a park in the western city of Rivne.
He says he was promised $2,000 (£1,520) to plant the bomb in a van used by Ukraine's military conscription service.
When I was connecting the wires, I thought it could explode then. I thought I might die, he told the BBC.
Vlad is one of hundreds of children and older teenagers who the Ukrainian government alleges have been recruited online by Russia, and offered payment to carry out sabotage and other attacks against their own country. His name has been changed to protect his anonymity.
He says he was told to set up the phone to live-stream the scene to his handler so they could remotely detonate the device when somebody entered the vehicle.
However, Ukraine's SBU security service had been watching and foiled the attack. Vlad - now 18 - is awaiting trial on terrorism charges that potentially carry a 12-year prison sentence.
Sitting in Rivne's heavily guarded detention centre with his lawyer beside him, he acknowledges that he could have helped kill somebody.
I did think about it. But nobody likes conscription officers, he says. I thought: Well, I'll be like everyone else.
The SBU says that over the last two years more than 800 Ukrainians have been identified as having been recruited by Russia - 240 of them minors, some as young as 11.
However, cyber security expert Anastasiia Apetyk, who teaches courses about internet safety in Ukraine, is aware of even younger cases. They tried to recruit children aged nine or 10, she says.
Andriy Nebytov, Deputy Head of Ukraine's National Police, says there is a deliberate strategy to seek out the vulnerable who can be manipulated.
Children do not always fully realise the consequences of their actions, he says.
The SBU says recruitment primarily takes place on the Telegram app, but also on TikTok, and even on video game platforms. Officials say those who are recruited are almost always motivated by money rather than pro-Russian sympathies.
Vlad had joined two Telegram channels and posted that he was looking for remote work. Within half an hour, a man calling himself Roman replied. When they later talked on the phone, Vlad says Roman spoke Russian with a street accent.
Vlad says he was initially reluctant but was persuaded to take on a series of increasingly dangerous tasks.
The payments ranged from $1,500 for setting fire to a post office to $3,000 for a bank.
Ukrainian officials have publicly named members of Russia's intelligence agencies they suspect of acting as handlers to saboteurs. The BBC has not been able to independently verify that the Russian state itself is responsible.
Meanwhile, Vlad has a message for others tempted by the recruiters. It's not worth it. They will either cheat you, and then you will end up in prison just like me, or you can take a bomb in your hands and it will simply blow you up.
