Kyiv has opened thousands of probes against Ukrainians suspected of collaborating with Russian forces since Moscow launched its full-scale invasion of Ukraine in February 2022, though arrests of minors are rare.

The Security Service of Ukraine (SBU) said Russia tasked the girl with passing on the locations of air defence systems in the region, which borders Belarus, a Moscow ally.

The SBU claimed the girl carried out reconnaissance during taxi rides and passed over sensitive information via encrypted online messenger services.

It said she was detained while taking photographs of a defence facility.

"The SBU seized a mobile phone with evidence of intelligence and subversive activities in favour of Russia," it added, saying the girl had been charged with high treason and was in custody.

The SBU said separately on Wednesday that it had detained six people in the Kyiv and southern Mykolaiv region for carrying out sabotage and arson attacks for Russia on railway and energy facilities.