MADRID — Taxi drivers protesting against Uber and other ride-hailing services clashed with the police in Madrid on Wednesday, cutting off a highway that rings the capital and picketing the opening of an international tourism fair.

The capital’s taxi drivers are in the third day of an indefinite strike, and intensified their protests in response to an apparent victory for their counterparts in Barcelona, who began striking on Friday. The regional government there said late Tuesday that it would ban ride-hailing companies from carrying passengers who booked less than an hour in advance, a proposal that has left Uber and others threatening to suspend services.

By noon, the authorities in Madrid said that 11 people had been injured in clashes in the capital on Wednesday, including five police officers.

King Felipe VI and Queen Letizia were ushered into the opening of Madrid’s annual tourism fair though a side entrance under heavy escort, as police officers charged against drivers who burned tires and containers to block road access.