Hundreds of thousands of people took to the streets of Catalonia's capital Barcelona on Sunday to express their opposition to declaring independence from Spain, showing how divided the region is on the issue.

A crowd estimated by local police to number 350,000 waved Spanish and Catalan flags and carried banners saying "Catalonia is Spain" and "Together we are stronger." They poured into the city center after politicians on both sides hardened their positions in the country's worst political crisis for decades.

Two more Catalonia-based companies set board meetings for Monday to decide whether to shift their head offices out of the region, adding to the intense pressure Catalan leader Carles Puigdemont is under to back away from declaring independence when he addresses the regional parliament on Tuesday.