Thousands of Catalan students went on strike Thursday in Barcelona to protest high education prices and show support for jailed regional leaders.

The demonstrators demanded a 30-percent reduction in university fees, which have increased 67 percent since 2012.

They also called for release of jailed separatist leaders, who they view as political prisoners in their campaign to break away from Spain.

The students marched through the streets of Barcelona, waving separatist Catalan flags, firing smoke bombs and holding up signs.

Spain has seen massive demonstrations in Barcelona in recent weeks to protest the jailing of top Catalan separatist leaders for misuse of public funds, sedition and rebellion — charges that carry a prison sentence of 30 years and imply that a "violent uprising" took place — over their separatist push.

The country is also pushing to extradite former Catalan leader Carles Puigdemont from Germany to face similar charges.