Update 2019-10-15: Protesters also blocked railway tracks and roads in Barcelona and other parts of Catalonia on Monday (14 October). A high-speed train from France was stopped in Girona. Security forces used foam bullets during the protests. Dozens of people were injured. At least 110 flights were cancelled at Barcelona airport. Protesters also gathered at Plaça de Catalunya and on Gran Via.
Protest marches to Barcelona will be held from Wednesday (16 October). Student groups will also begin a strike on Wednesday (16 October). A mass rally and a general strike will be held in Barcelona on Friday (18 October).
Further protests are to be expected in Barcelona and other parts of Catalonia in the upcoming days.
Update 2019-10-14: Protests by thousands of independence supporters at Barcelona airport have led to clashes with security forces. By Monday evening (14 October, local time) more than 30 people had been injured. The demonstrators had tried to paralyze parts of Barcelona-El Prat airport and block access routes. Dozens of flights had to be cancelled and many others were delayed.
2019-10-14: On Monday (14 October) the Spanish Supreme Court sentenced multiple leaders of the Catalan independence movement to several years in prison. Due to subsequent demonstrations by separatists, the metro and train connections to Barcelona–El Prat Josep Tarradellas Airport were closed.
Heightened security measures and operations of security forces are to be expected. Violent clashes between protesters and security forces are possible. Travellers are advised to exercise caution, to strictly avoid demonstrations, road blockades, large gatherings, and deployments of security forces, and to follow instructions from security forces.
Deutsche Welle, Yahoo News