MADRID (AP) — The Latest on protests in Catalonia (all times local):

3:05 p.m.

Convicted Catalan activist Jordi Cuixart says the politicians and activists sentenced for their roles in a 2017 push for Catalan independence will take their case to the European Court of Human Rights, claiming that the court conviction is a European affair.

Cuixart told The Associated Press by email via his lawyer Tuesday that "we have the moral obligation to denounce this (Spain's) authoritarian drift and appeal to European citizens to defend human rights."

Cuixart, who heads Omnium Cultural, one of two activist groups that has spearheaded the Catalan independence movement, said the 12 convicted Monday must first appeal to Spain's Constitutional Court before approaching Europe.

Cuixart was sentenced to nine years. He said they would also seek an amnesty "as a resolution to this political conflict."

11:15 a.m.

Authorities in Catalonia say three people were arrested and more than 170 injured, including about 40 police officers, during clashes between protesters and baton-wielding anti-riot police at Barcelona's international airport and elsewhere across the northeastern Spanish region.

The clashes that started late Monday stemmed from an online call by Tsunami Democratic, a loose grassroots group, following the conviction of a dozen separatist leaders at the forefront of Catalonia's secession bid two years ago.

Interior Minister Fernando Grande-Marlaska said authorities are investigating the group.

Spain's airport operator, AENA, said more than 1,000 flights were scheduled to operate normally in Barcelona Tuesday, after at least 110 were cancelled the day before.

Thousands of passengers were stranded at the airport, with many forced to walk with their luggage on highways and across fields.