A Spanish judge has issued European Arrest Warrants (EAW) for sacked Catalan leader Carles Puigdemont and four of his allies who went to Belgium.
The five failed to attend a high court hearing in Madrid on Thursday when nine other ex-members of the regional government were taken into custody.
One of those detained has been freed on bail of €50,000 (£44,000; $58,000).
They all face charges of rebellion, sedition and misuse of public funds for pursuing Catalan independence.
The regional parliament voted to proclaim an independent republic a week ago, following an illegal referendum on independence organised by the Catalan government on 1 October
No other country recognised the move and the Spanish central government moved swiftly to impose control, using emergency powers under the constitution.