MADRID (AP) -- Catalonia's regional government is mulling when to declare the region's independence from Spain in the wake of a disputed referendum that has triggered Spain's most serious national crisis in decades.
The region's pro-independence president, Carles Puigdemont, who has said an independence declaration will come in a few days, is due to deliver a speech later Wednesday.
Spain, which declared Sunday's referendum illegal and invalid, is bitterly opposed to any independence move. Spain's conservative government has said it will respond with "all necessary measures" to counter Catalan defiance, and is holding talks with opposition leaders to forge a consensus over what to do in response.
It's anybody's guess what might happen if the northeastern region of Catalonia does actually try to secede. Spain could intervene to take over the regional government or it could even declare a state of emergency and impose martial law.
In a special national address Tuesday night, Spain's King Felipe VI came out strongly against the actions of Catalan authorities, arguing that they had deliberately bent the law with "irresponsible conduct."
The Spanish state, he went on, needed to ensure constitutional order and the rule of law in Catalonia, which is the richest region of Spain.
Catalonia says some 2.3 million people — less than half the region's electorate — voted in the referendum. Many of those opposed to independence are thought to have stayed at home after the referendum was deemed illegal by Spanish courts. Of those who voted, some 90 percent voted yes to independence.
Going down the independence route won't be easy for Catalonia. The region doesn't have any powers over defense, foreign affairs, taxes, ports or airports, all of which are in the hands of the Madrid government.
The crisis in Spain grew more acute Sunday when some 900 people were treated in hospital following clashes with police ordered to prevent to the vote.
On Tuesday, huge crowds held street protests and unions staged a strike in Catalonia to protest against the alleged police brutality. There were no reports of trouble.
Spain's National Court on Wednesday said it will quiz two senior officers of Catalonia's regional police force and the leaders of two pro-Catalan independence civic groups who have been placed under investigation for sedition.
The court said the four will be questioned on Friday about their roles in demonstrations Sept. 20-21 in Barcelona when Spanish police arrested several Catalan government officials and raided offices in a crackdown on preparations for the referendum.
Spanish authorities say the demonstrations hindered the police operation. During the rallies, there were some disturbances and two police vehicles were thrashed.
The four include regional police chief officer Josep Lluis Trapero and Jordi Sanchez, the head of the Catalan National Assembly that has been the main civic group behind the independence movement.