At least 13 people died and over 100 were injured when a van ploughed into pedestrians in the busy tourist area of Las Ramblas.

Barcelona confirmed they will wear black armbands this weekend in tribute to the victims, while a minute's silence will also be held ahead of the club's opening match of the season with Real Betis at the Camp Nou on Sunday, as well as at matches across Spain.

Messi took to Instagram on Thursday night to express his shock and sadness at the attack.

He wrote: "I would like to send my condolences and all my support to the families and friends of the victims of the terrible attack on our beloved Barcelona, as well as totally reject any act of violence.

"We are not going to give up, we are many more who want to live in a world in peace, without hate and where respect and tolerance are the basis of coexistence."

Barcelona condemned the attack and expressed its "profound sorry and utter disgust" at Thursday's atrocity.

A club statement read: "FC Barcelona wants to express its profound sorrow and utter disgust at the terrorist attack that has hit the heart of our city, la Rambla de Barcelona.

"The club wishes to send our support and thoughts to the victims, their families and friends as well as the people of Barcelona and its visitors."

Luis Suarez took to social media to post a picture of a black armband, alongside the caption: "Very shocked for what happened in Barcelona. All my support to the city and families!"

Brazil international Neymar, who recently left the Catalan club to join Paris Saint-Germain in a world-record transfer, tweeted: "May God comfort all families #PrayForBarcelona I love you BARCELONA."

Barcelona's cross-city rivals, Espanyol, also released a statement offering their support to those affected by the attack.