This is the moment when a group of street musicians inadvertently filmed one of the twin explosions outside a football stadium in Istanbul that killed 38 people on Saturday night.

In the video, two young men playing guitar and singing can be seen sitting on a bench when a bright flash appears in the cityscape behind them.

The man filming can be heard saying “there was an explosion”, and as the others turn to look the sound of the blast hits them, causing them to jump up off the bench.

The explosion is believed to be one of the two which struck the newly-built Vodafone Arena, home to Istanbul's Besiktas football soccer team.

The Turkish government has blamed Kurdish militants for the bomb attack, which witnesses said was followed by the sound of gunfire.

Interior Minister Suleyman Soylu said the first explosion, a car-bombing, came around two hours after the end of the match between Besiktas and Bursaspor at an assembly point for riot police. The second came as police surrounded the suicide bomber in the nearby Macka park.

"According to the latest information we have received, 38 of our nation's children have reached martyrdom after last night's cruel attack," Soylu told a news conference.

"These cruel attacks do not discourage us, to the contrary they brings us together as a nation."