MOSCOW (AFP) - Russian President Vladimir Putin sat at a piano and picked out the melody of a popular Soviet-era song on Wednesday as a group of students sang along.

The strongman leader sat down at a grand piano at a top Moscow physics institute and played the song Moscow Windows while members of a male student choir joined in, the state RIA Novosti news agency reported.

The 61-year-old president admitted he cannot sing, however.

"I don't sing too well, but I try to play. I'll start and you sing along," the pro-government Izvestia daily quoted him as saying.

"I love to dream under windows/I can read them like a book," the choir sang as Putin played, a video posted on YouTube showed.

At the end of the piece students clapped and shouted "bravo" while Putin raised his arms in acknowledgement.

Putin has previously shown off his skill at the piano, playing a patriotic Soviet song titled Where Does The Motherland Begin? at a theatre in 2011 and Blueberry Hill at a charity gala in 2010.

Putin has yet to react publicly to an escalation of protests in neighbouring Ukraine, where at least two activists were shot dead on Wednesday in the latest outbreak of violence.