Scotland's First Minister Nicola Sturgeon called on Spain to "change course" Sunday, as at least 91 people were injured in Catalonia over a banned independence referendum.
Sturgeon, who leads the pro-independence Scottish National Party, has backed the right of the Catalan government to hold a vote on separation.
She said on Twitter she was "increasingly concerned by images from Catalonia," as Spanish police forced their way into many polling stations and fired rubber bullets at protesters.
"Regardless of views on independence, we should all condemn the scenes being witnessed and call on Spain to change course before someone is seriously hurt," Sturgeon wrote.
"Let people vote peacefully."
Spain's central government and courts have ruled that the Catalan vote is unconstitutional.
A total of 337 people visited hospitals and health centres on Sunday, a spokeswoman for the Catalan government's health department said. So far 91 have been confirmed as injured.
Sturgeon has deferred plans for another referendum on Scottish independence.
The SNP and other pro-independence parties in 2014 lost a vote to leave the United Kingdom, polling 45 percent against 55 percent who opted to remain.
Scottish Conservative leader Ruth Davidson also expressed alarm at the violence in Catalonia.
"Everyone will be shocked by the disturbing scenes coming from Catalonia. It is clear that this is a fast-moving situation, but we would urge the authorities to exercise restraint. Nobody wants to see people hurt," Davidson said.