A giant banner with a portrait of Russian President Vladimir Putin and the word "Peacemaker" has been unfurled from a New York City landmark.

Police are investigating after the appearance of the mysterious poster, measuring 20ft by 30ft, hanging from the side of Manhattan Bridge.

Officers took down the banner a short time after being alerted to its presence on Thursday afternoon.

A spokesman for the city police department said: There are no details on why or who, it has to be investigated.

Surveillance footage on the bridge and in nearby areas is being examined in a bid to trace those responsible.

The stunt comes amid heightened tensions between Washington and Moscow over Ukraine and Syria.

Russia has also been blamed of a series of cyber attacks on the Democratic Party during the US presidential campaign.

(c) Sky News 2016: Vladimir Putin ‘peacemaker’ banner hung from Manhattan Bridge