Protesters, joined by "uncontrollable young rioters", blocked traffic on part of the A16 in Calais on Thursday night by making incursions into three access areas of the motorway.
"Yellow vests" invaded Thursday night the A16 motorway in Calais, causing clashes with police and significant disruption, told AFP a police source.
Since the beginning of the evening, protesters, joined by "uncontrollable young runners , " sporadically incurs in three access areas of the A16 to block road traffic in both directions, reported source.
"These incursions are criminal and irresponsible and are acts of vandalism," she said, adding that groups of "thugs" have disposed of logs across the road, at the risk of causing accidents.
"A young driver was not able to avoid these obstacles and a tragedy was avoided" , a witness told an AFP correspondent. No injuries were reported Thursday night.
These movements caused a traffic jam on the eastern part of the A16, near Marck-en-Calaisis, as well as on the harbor bypass serving the ferry terminal that connects Calais to Dover, in Great Britain.
In this area, many trucks were stopped, police fearing attempts to intrude migrants in truck trailers.
This rise in tension comes on the 6th day of rallies on this nerve center of the movement, while demonstrators call to gather again Friday in Calais to determine the follow-up to their actions.