Thousands have taken to the streets in Morocco's northern city of Tangier to protest over high prices for water and electricity, in the nation's largest protest since pro-democracy marches in 2011 demanding political reforms.

Large-scale protests are rare in Morocco, where the king still holds ultimate sway. When pro-democracy unrest toppled leaders in Tunisia, Egypt and Libya in 2011, the palace managed to calm similar protests with a combination of limited reforms, spending and tougher security.

Saturday night's time demonstration was the latest in a series that started two weeks ago. It took place a day after authorities and the company running the services proposed measures to calm unrest against what protesters see as high prices and administrative mismanagement.

Water, wastewater and electricity businesses in the cities of Tangier and neighboring Tetouan have been operated since 2002 by Amendis, an affiliate of France's Veolia Environnement.

Redal, another Veolia subsidiary, is operating in the capital Rabat, Sale and municipalities of Temara and Bouznika.

"Amedis go home, Tangier is not yours," chanted thousands of protesters in the city centre where dozens of small protests from different neighbourhoods converged.

The authorities deployed hundreds of riot police and closed streets. Many cafes and stores in the city switched off their lights and lit candles in support of the protest.

"Enough is enough. We have been protesting for years now against that company," said Mohamed Tadlaoui one of the organisers of the demonstration. "Now it is time for them to leave, and a public company should take over."