This is an archived article that was published on sltrib.com in 2016, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Lisbon, Portugal • Several thousand taxis snarled morning rush-hour traffic in the Portuguese capital Monday in the latest European protest against ride-hailing apps.

Portuguese taxi drivers complain that companies such as Uber and Cabify are not covered by the same tax, training and safety regulations as they are. They want the government to adopt specific legislation for ride-hailing services.

Two labor groups representing Portugal's around 13,000 taxi drivers organized the long line of slow-moving taxis that snaked through Lisbon in the second such protest in six months.

Hundreds of police were on standby in case of violence, and sporadic scuffles broke out as taxi drivers confronted vehicles they claimed were working with Uber. Police arrested at least two protesters after a car was smashed. Riot police were deployed on roads around Lisbon's international airport after some taxi drivers abandoned plans to head to Parliament and tried to block access routes to terminals.

Other European Union countries have also witnessed demonstrations by traditional taxi drivers against the increasingly popular ride-hailing services.