PARIS (AP) Protests and strikes against unpopular pension reforms kicked off again Tuesday across France, with police security ramped up against feared violence and government warnings that radical demonstrators intend to destroy, to injure and to kill.

Fears that violence could mar the demonstrations prompted what Interior Minister Grald Darmanin described as an unprecedented deployment of 13,000 officers, nearly half of them concentrated in the French capital.

Protests got underway peacefully Tuesday morning, with large crowds in multiple cities. In Paris, striking railway workers with burning flares and flags invaded and blocked train tracks serving one of the capitals main stations, Gare de Lyon.

Police were braced for violence later in the day. The interior minister said more than 1,000 radical troublemakers, some from overseas, could latch on to marches planned in Paris and elsewhere.

They come to destroy, to injure and to kill police officers and gendarmes. Their goals have nothing to do with the pension reform. Their goals are to destabilize our republican institutions and bring blood and fire down on France, the minister said Monday in detailing the policing measures.

Union leaders and political foes of President Emmanuel Macron blame his government for protest violence that has flared in recent weeks, saying his push to raise Frances legal retirement age from 62 to 64 sparked it.

Critics also allege that police officers used excessive force against protesters. A police oversight body is investigating multiple claims of wrongdoing by officers.

The striking railway workers at Gare de Lyon marched behind a banner that alleged: The police mutilates. We dont forgive!

The new wave of protests was the 10th time since January that unions have called on workers to walk out and for demonstrators to flood the nations streets against Macrons proposal.

Unable to get a majority in parliaments lower house for the unpopular reforms, Macron rammed them through using a special constitutional power , further inflaming protesters anger.

Everybody is getting madder, said Clment Saild, a train passenger at Gare de Lyon who said he supports the strikes despite their impact on transportation and other services.

I am 26, and I wonder if I will ever retire, he said.

Another passenger, Helene Cogan, 70, said: French people are stubborn and things are getting out of hand.

Jade le Deley in Paris contributed.