Police had arrested 135 people before large marches were set to begin in cities across France, Interior Minister Laurent Nunez says.
Nunez told reporters that there had been no major incidents so far on Saturday.
He had earlier announced the deployment of 70,000 officers on the streets.
More than 1000 checks had been carried out in the Paris region, the minister said.
Many dangerous items were seized including the heavy balls used for playing the French game boules, slingshots and an airsoft weapon.
The checks were "extremely productive," Nunez said, adding that the police remained very cautious and were still far from the end of the day.
Authorities fear fresh riots as country-wide demonstrations are planned again, with authorities worried about a repeat of the levels of violence seen the previous weekend.
The Paris Police Prefecture said it was carrying out "massive checks," particularly at railway stations and on public transport, "to deter those who wish to enter the capital with malicious intent".
According to initial reports, the situation in Paris was "calm".
Nunez said there had been numerous calls for violence and looting, which were clearly messages from rioters.
The interior minister said a number of demonstrations had already been banned.
Rallies would be allowed if organisers provided stewards "and on condition that they naturally do not take place in places where looting, disturbances of public order and the like could occur".
Trade unions were outraged that the march they had registered in Paris had been relocated by the prefecture to the outskirts of the city.
The Administrative Court confirmed the route in an urgent ruling.
At midday, the first demonstrators gathered at the Porte d'Italie, from where the protest march was due to start at 2pm.
Due to fears of a repeat of the riots and looting, bans on gatherings in certain areas and curfews were imposed in several other French cities.
In Nice, where all gatherings are banned according to the prefecture, police officers, gendarmes and special forces were deployed in the city centre.
Young people across France have been demonstrating for weeks for better equipment in schools.
Last weekend, other groups joined their rallies in numerous cities, including protests against the high cost of living.
Serious clashes broke out on the fringes of the protests.
