Up to 30 officers were injured when police battled police in a bizarre clash in downtown Madrid today.
Riot police, who fall under the jurisdiction of the Interior Ministry, fought to disperse Madrid city police trying to march on town hall to press salary and other demands.
Spanish television showed truncheon-wielding National Police hitting off-duty, plainclothes city police on a main avenue in the old quarter of the city, and firing tear gas canisters.
The city police chanted "we are police, not terrorists."
City police asked the Interior Ministry on Monday for permission to stage the rally, and after getting no reply asked again in vain on Wednesday, then finally went ahead with the protest, city police spokesman Mr Candido Albarran said.
The ministry said it did get the request until yesterday and by then it was to late to authorize. He said 26 city officers were injured, and the ministry said four of its staff were hurt in the skirmish.
Mr Albarran said city police want better equipment, more staff and more money to offset a 40-hour work week that contrasts with a 35-hour week that municipal employees put in.
AP