Anti-independence campaigners plaster Barcelona with Spanish flags

The flags appeared overnight and have cropped up this morning (Thursday) in the Sarriá-Sant Gervasi neighbourhood and on the Avenida Diagonal, as well as in satellite towns outside the main metropolitan area including Sant Cugat del Vallès and L'Hospitalet de Llobregat.

Although the movement behind them is not known and the exact number of people involved unclear, the Mossos d'Esquadra – Catalunya's answer to the Guardia Civil – caught seven individuals red-handed (or red-and-yellow-handed) sticking around 50 flags to public fixtures on the Paseo de la Bonanova in the early hours of the morning.

Three of them were said to be aged under 18, and have been fined for defacing municipal property.

But MP for Catalunya Enric Millo takes a more lenient view.

Whilst he is 'not personally aware' of the 'initiative', Millo attributes the flags to 'a group of people with the desire to express themselves and doing so in the best way they know how'.

“Everyone should be free to express their opinions publicly,” the central government representative stressed.

The photograph shows one of the flags, in the Plaça de les Glòries, by @PublicoJ on Twitter.