Joggers, taxi drivers, players of Pokemon Go and senior Russian officials are seeking an explanation of why mobile phone apps that use GPS are malfunctioning in central Moscow.
A programmer for Russian internet firm Yandex, Grigory Bakunov, said Thursday his research showed a system for blocking GPS was located inside the Kremlin, the heavily guarded official residence of Russian President Vladimir Putin.
Users of GPS have complained on social media in recent months that when they are near the Kremlin their GPS-powered apps stop working or show them to be in Moscow's Vnukovo airport, 29 kilometers (18 miles) away.
The problem has frustrated those requesting taxis via services such as Uber or looking to catch Pokemons in the popular game played on mobile devices. Large numbers of people running the Moscow marathon last month complained that their jogging apps lost track of how far they had run when they passed the Kremlin.
"I got 40 kilometers added on to my distance. It happened by the Kremlin," marathoner Andrey Yegorov wrote on Facebook as part of a discussion by runners.
The relocation to Vnukovo airport, according to Bakunov, suggests the purpose of the disruption may be to prevent drones flying over the Kremlin. GPS often automatically stops drones from flying near airports because of the danger they present to aircraft. Any device mimicking this would be able to halt overflights.
The first anomaly was recorded in June, according to Russian media reports, which have also suggested that the GPS interference comes and goes in a pattern.
Putin's spokesman Dmitry Peskov said Thursday he did not know why the malfunction was occurring and admitted experiencing the problem himself when driving recently. Peskov redirected questions to Russia's Federal Guards Service, which is responsible for protecting the Kremlin and senior Russian officials.