Protests have erupted in Barcelona after Spain's Supreme Court sentenced nine Catalan separatist leaders to between nine and 13 years in prison.

Thousands of demonstrators blocked road access to Barcelona's El Prat airport. More than 100 flights were cancelled. Riot police charged protesters, who threw rocks, cans and fire extinguishers, AFP news agency reported.

The separatist leaders were convicted of sedition over their role in an illegal independence referendum in 2017.