PARIS -- French President Emanuel Macron called Friday for calm as authorities prepared to deploy armoured vehicles and thousands of security forces for a possible fifth-straight weekend of violent protests on the streets of Paris.

The "yellow vest" movement, which began its demonstrations Nov. 17 initially to protest an increase in fuel taxes, soon morphed into an expression of rage about the high cost of living in France and a sense that Macron's government is detached from the everyday struggles of workers.

"Our country needs calm. It needs order. It needs to function normally again," Macron said in Brussels, where he attended a European Union summit.

Later, he travelled to Strasbourg to express his condolences in the eastern French city where a gunman killed four people and wounded a dozen more after opening fire Tuesday near a Christmas market. The suspected attacker was killed Thursday in a shootout with police. Macron thanked some of the hundreds of security forces that had helped in the Strasbourg manhunt.

Macron acknowledged in a speech earlier this week that he's partially responsible for the anger displayed by the "yellow vest" protesters -- whose movement takes its name from the safety garb that all French motorists must carry. He has announced measures aimed at improving workers' spending power. But he has so far refused to reinstate a wealth tax that was lifted to spur investment in France.

"I don't think our democracy can accept to function with a dialogue that is carried out only with the occupation of the public domain, only by elements of violence," Macron said.

He insisted he had heard the protesters' concerns and defended his promises to speed up tax relief. He has ignored calls for his resignation, which is now among the protesters' various demands.

Paris Police Chief Michel Delpuech told RTL radio that security services intend to deploy about 8,000 officers and 14 armoured vehicles in the capital, the same numbers as last weekend. Since the start of the protests, six people have died in protest-related incidents and 1,407 people have been injured, 46 of them seriously, according to government figures.

For the second straight weekend, several weekend French league soccer matches were postponed at the request of authorities.

Some trade unions are now calling for rolling strikes across the country.

"The best action is to go on strike," said Philippe Martinez, the head of leftist trade union CGT. "There are inequalities in this country and we need to make big company bosses pay."

Delpuech said more groups of officers will be deployed this weekend to deter vandals, who last weekend roamed the elegant Champs-Elysees area, smashing store windows and looting stores. On Friday, shops were boarding up their store windows ahead of the protests and many planned to close.

"Last week, we pretty much handled the 'yellow vests,' but we also witnessed scenes of breakage and looting by criminals," Delpuech said. "Our goal will be to better control this aspect."

Police arrested more than 1,000 people in Paris last weekend, and 135 people were injured, including 17 police officers.

Amnesty International also urged authorities to use restraint, describing the security forces' response to the protests as "extremely heavy-handed."

"Police used rubber bullets, sting-ball grenades and tear gas against largely peaceful protesters who did not threaten public order and the organization has documented numerous instances of excessive use of force by police," the group said in a statement.

"Whilst policing demonstrations is a difficult task and some protesters have committed unlawful and violent acts, it is essential that both French law and international human rights law is respected," the statement quoted Rym Khadhraoui, Amnesty International's West Europe researcher, as saying.

Interior Minister Christophe Castaner urged protesters to demonstrate peacefully, citing the Strasbourg attack and the work of the security services that were mobilized in the manhunt for the suspect, 29-year-old Cherif Chekatt, who was shot and killed by police.

"I can't stand the idea that today people applaud police forces and that tomorrow some people will think it makes sense to throw stones at us," Castaner said from Strasbourg.

One group of demonstrators has urged a nonviolent protest on the Place de la Republique in Paris under the slogan "Je Suis Strasbourg" ("I am Strasbourg") to show solidarity with the victims of the attack. The slogan evokes the "Je Suis Charlie" motto used by supporters of freedom of speech after a 2015 attack in which 12 people were killed at the French satirical weekly newspaper Charlie Hebdo.

Associated Press writers Samuel Petrequin and Raphael Satter in Paris and Angela Charlton in Brussels, Belgium, contributed.