Russian President Vladimir Putin's speech during a ceremony marking the anniversary of the annexation of Crimea from Ukraine was cut off from television on Friday, prompting speculation about the causes, before the Kremlin said it was due to a technical glitch.

As Putin was giving his speech in Moscow's crowded Luzhniki Stadium on the occasion of the eighth anniversary of the annexation of Crimea, the broadcast suddenly turned into patriotic songs being performed during the celebration.

Later, Russian television showed the full speech, which ended a few seconds after the cut-off time, and Putin was seen leaving the stage while thousands of attendees were waving Russian flags.

The Russian RIA news agency quoted Kremlin spokesman Dmitry Peskov as saying that the broadcast was interrupted due to a server malfunction.