Only authorised union protests will be allowed in French towns and cities on Saturday, President Emmanuel Macron has said, after demonstrations across the country turned violent last weekend.

Speaking as some cities including Lyon and Nice imposed complete bans, Macron said “illegitimate” protests would not be allowed but unions would be offered alternative routes so that businesses could be protected.

Big demonstrations against the high cost of living and school conditions were overshadowed last Saturday by riots and looting that saw business and historic buildings destroyed.

Interior Minister Jean-Didier Berger said police deployments would be increased by 20% compared to last weekend, after the government was accused of being blindsided by the scale of the unrest.

France’s justice minister said on Thursday that 217 people had been jailed over last weekend’s disorder after being convicted in fast-track trials, with that number expected to rise.

Gérald Darmanin said 2,700 people had been arrested across France and more than 1,000 have appeared in court.

Half of those detained had no prior criminal record, he said, according to Le Figaro newspaper.

Macron met intelligence services and ministers on Thursday, to prepare for the next national day of protests on Saturday.

“The general recommendation is that there should be no demonstrations. Those who want to continue to demonstrate, when they are trade union organisations, will have alternative routes proposed by the prefects,” the French president announced. “When they’re not union organisations, wherever possible, they’ll be banned.”

He attacked what he called “political and even seditious acts organised by far-left groups that aim to bring down the Republic”.

Curfews were imposed in several cities in the aftermath of the weekend rioting, and Macron said the government wanted a return to calm.

The gilets jaunes (yellow-vest) movement was behind many of last weekend’s protests and Paris authorities have said several of their proposed marches have been banned.

In Lyon, France’s third-biggest city, regional authorities have imposed a blanket ban on demonstrations.

“In light of the mobilisation that is circulating and in view of the events of 17 October, the prefect has decided to prohibit by decree any demonstration in the city of Lyon this Saturday,” the Rhône prefecture said in a statement.

Similar announcements have been made in Toulon on the south coast, the centre of Rouen in the north-west, and Grenoble in the east.

Partial curfews variously restricting the movement of young people and gatherings have been in place this week in cities including Marseille, Bordeaux, Nice and Lyon in the south as well as Lille and other towns in the north.

Prime Minister Sébastien Lecornu promised a “massive” deployment of police officers this week to deal with any unrest this weekend, but some officers have told French media they are not trained to deal with large crowds.