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.
Mr Puigdemont has said he will not return to Spain unless he receives guarantees of a fair trial. Belgium will "study" the warrant, a spokesman for the state prosecutor told AFP news agency.
The regional parliament in Catalonia voted to proclaim an independent republic a week ago, following an illegal referendum on independence organised by the Catalan government on Oct 1.
No other country recognised the move and the Spanish central government moved swiftly to impose control, using emergency powers under the constitution.
- Source: BBC News