Taxi-drivers in the Spanish capital seeking tighter regulation of Uber and other ride-hailing services called off their indefinite strike on Tuesday after 16 days during which they obtained no concessions from the Madrid regional government.

Madrid’s refusal to accept drivers’ demands came after ride-hailing companies Uber and Cabify said last week they were suspending their services in Barcelona in response to the regional government’s imposition of limits on how they operate in the city.

Union representatives in Madrid said the strike had demonstrated the unity and power of the drivers, which would help them continue the fight for their demands.

“It is a long war, in which you can lose battles, but in the end I’m sure we can win,” Julio Sanz, head of the Taxi Federation union, told reporters.

The city’s taxi drivers started the protests on Jan. 20 against the private services, which offer rides that often undercut taxi prices and can be hailed via the internet rather than in the street.

Last week, riot police backed by a fleet of tow trucks had to clear hundreds of vehicles blocking the capital’s Paseo de la Castellana thoroughfare.

In September, Spain’s government gave ride-hailing companies four years to comply with regulation granting them just one new licence for every 30 taxi licences. The cab drivers are demanding stricter regulations now.

Following protests by Barcelona taxi-drivers, the Catalan government had ruled that ride-hailing services could only pick up passengers after a 15-minute delay from the time they were booked.