Catalan police intervene as rival demonstrations by separatists and Spanish police take place in central Barcelona.

Police have clashed with protesters who gathered in downtown Barcelona to protest another march in support of Spanish police.

Saturday’s protests come ahead of the anniversary of the 2017 Catalan independence referendum.

Separatists threw paint at police, covering anti-riot shields, police vans and the pavement in a downtown square in a panoply of bright colours.

The protesters also threw projectiles at police. Officers responded with baton attacks to keep them back.

Video footage showed agents forming a barrier pushing back a crowd of protesters, some of whom are waving the Catalan flag.

CATALONIA | Police in Barcelona using violence against pro-independence #Catalans demonstrating the violence used last year during the independence referendum. pic.twitter.com/kbgWzK6Uuj — Vocal Europe (@thevocaleurope) September 29, 2018

Barcelona’s mayor Ada Colau asked to “avoid confrontation” between separatists and people protesting in support of Spanish police, who are demanding better pay.

The separatists filled a downtown square in Barcelona, many spending the previous night there, to force the regional government to alter the route of the march by the Spanish police supporters.

Tensions are running high in the northeastern region of Spain nearly a year after Catalans voted to secede in a referendum that had been declared illegal by Spanish authorities.

There were shouts of “October 1, we don’t forget nor forgive” among the separatists who had gathered on Saturday.

Hundreds were injured in clashes between national police and civilians on the day of the referendum as police tried to stop people from voting. Rights groups accused police of using excessive force.

In the aftermath of the vote, the Spanish government dissolved Catalonia’s parliament and imposed direct rule, which ended in June with the swearing-in of a new regional government.