MADRID (AP) — The former head of Catalonia's regional police and three others are standing trial on charges of rebellion and sedition for their alleged roles in the illegal bid by the Catalan regional government to break away from Spain in 2017.

The trial starting Monday in the National Court could inflame secessionist sentiment again in Catalonia after several weeks of calm in the northeastern region. It also comes as new Socialist Prime Minister Pedro Sánchez promises to try to resolve the regional conflict with political talks rather than legal actions.

The state prosecution has asked for former Mossos police chief José Luis Trapero to be sentenced to 11 years on charges of rebellion for allegedly conniving with regional authorities in the failed secession push led by former Catalan regional President Carles Puigdemont and his deputy, Oriol Junqueras.

Puigdemont, now a European Parliament member, fled Spain to Belgium following the push. Spain is seeking his extradition. Junqueras and eight other Catalan politicians and activists received prison sentences last October for their roles.

Also charged with rebellion are former Catalan regional interior ministry official, César Puig and former regional police director, Pere Soler. Senior regional police officer Teresa Laplana is charged with sedition.

The trial is expected to last two months and several of those in prison are expected to testify.