Journalists wait outside the Spanish Supreme Court in Madrid, Tuesday, Feb. 12, 2019. Spain is bracing for the nation's most sensitive trial in four d...
Journalists wait outside the Spanish Supreme Court in Madrid, Tuesday, Feb. 12, 2019. Spain is bracing for the nation's most sensitive trial in four decades of democracy this week, with a dozen Catalan separatists facing charges including rebellion over a failed secession bid in 2017. (AP Photo/Manu Fernandez)
A bus belonging to Spain's Civil Guard allegedly carrying Catalonian politicians and activists, arrives at the Spanish Supreme Court in Madrid, Tuesda...
A bus belonging to Spain's Civil Guard allegedly carrying Catalonian politicians and activists, arrives at the Spanish Supreme Court in Madrid, Tuesday, Feb. 12, 2019. Spain is bracing for the nation's most sensitive trial in four decades of democracy this week, with a dozen Catalan separatists facing charges including rebellion over a failed secession bid in 2017. (AP Photo/Manu Fernandez)
FILE - In this Friday, Oct. 27, 2017 file photo, Catalan Vice President Oriol Junqueras, center, is greeted after a vote on independence in the Catala...
FILE - In this Friday, Oct. 27, 2017 file photo, Catalan Vice President Oriol Junqueras, center, is greeted after a vote on independence in the Catalan parliament in Barcelona, Spain. Spain's Supreme Court is bracing to hold the nation's most sensitive trial in four decades of democracy this week with all eyes focused on its ability to stand up to concerted campaign by Catalonia's separatists to attack its credibility. Twelve high-profile Catalan separatists will face charges including rebellion for their role in a failed attempt to achieve secession for the prosperous north-eastern region in 2017. (AP Photo/Manu Fernandez, File)
FILE - In this Monday, Oct. 2, 2017 file photo, Catalan regional Vice-President, Oriol Junqueras, left, and Catalan President, Carles Puigdemont, atte...
FILE - In this Monday, Oct. 2, 2017 file photo, Catalan regional Vice-President, Oriol Junqueras, left, and Catalan President, Carles Puigdemont, attend a protest called by pro-independence supporters outside the Palau Generalitat in Barcelona, Spain. Spain's Supreme Court is bracing to hold the nation's most sensitive trial in four decades of democracy this week with all eyes focused on its ability to stand up to concerted campaign by Catalonia's separatists to attack its credibility. Twelve high-profile Catalan separatists will face charges including rebellion for their role in a failed attempt to achieve secession for the prosperous north-eastern region in 2017. (AP Photo/Manu Fernandez, File)
A bus belonging to Spain's Civil Guard allegedly carrying Catalonian politicians and activists, arrives at the Spanish Supreme Court in Madrid, Tuesda...
A bus belonging to Spain's Civil Guard allegedly carrying Catalonian politicians and activists, arrives at the Spanish Supreme Court in Madrid, Tuesday, Feb. 12, 2019. Spain is bracing for the nation's most sensitive trial in four decades of democracy this week, with a dozen Catalan separatists facing charges including rebellion over a failed secession bid in 2017. (AP Photo/Manu Fernandez)
A bus belonging to Spain's Civil Guard allegedly carrying Catalonian politicians and activists, arrives at the Spanish Supreme Court in Madrid, Tuesda...
A bus belonging to Spain's Civil Guard allegedly carrying Catalonian politicians and activists, arrives at the Spanish Supreme Court in Madrid, Tuesday, Feb. 12, 2019. Spain is bracing for the nation's most sensitive trial in four decades of democracy this week, with a dozen Catalan separatists facing charges including rebellion over a failed secession bid in 2017. (AP Photo/Manu Fernandez)
MADRID (AP) — Protesters have blocked highways in Spain's northeastern region of Catalonia, as the trial of separatist leaders gets underway in the country's Supreme Court in Madrid.
Tuesday's protests, which have also led authorities to close off some main roads in the Catalan capital of Barcelona, were timed with the start of arguably Spain's most consequential trial in four decades of democracy.
Twelve defendants are being tried for their roles in pushing ahead with a unilateral independence declaration based on the results of a secession referendum that ignored a constitutional ban. Some face decades in prison if they are found guilty of rebellion.
The proceedings are being broadcast live on television.
