Dozens of Calais migrants try to storm Channel Tunnel
Migrants entered restricted areas on the French side overnight, delaying and cancelling services, Eurotunnel said.
A spokesman for the firm called for "immediate action" from authorities to protect the tunnel and provide a solution to the migrant crisis.
Passenger services are back to normal but there are still delays to freight journeys, Eurotunnel said.
Freight lorries are queuing on the M20 for the second time this week.
Kent Police initiated phase two of Operation Stack - where freight traffic is queued on sections of the M20 - and closed roads at about 01:00 BST.
A spokesman for Eurotunnel said there had been "huge numbers of migrants" in and around the area on Friday night.
They said: "Up to 150 migrants stormed the tunnel, which caused disruption to services leading to delays and cancellations for customers.
"Eurotunnel wants immediate action from authorities to protect the tunnel - not enough is being done to stop the migrants."
Dan Cook, operations director at Europa Worldwide, a transport and logistics business, said "marauding mobs" of migrants were breaking into the company's vehicles.
Mr Cook said: "This isn't in lay-bys off the beaten track at night, this is in broad daylight on the motorways approaching Calais and what you see, to be blunt, is marauding mobs around trailers... climbing on board, breaking open backdoors with broadly no sign of any sort of policing to prevent it.
"If we were watching television in the UK and we were seeing mass groups of people wandering around the motorway climbing on vehicles I think we would be pretty outraged and we would expect the British authorities to do something about it."
He added that he believed French authorities had an "obligation" to protect people who use the country's roads.
Earlier this week lorry drivers in England faced days of misery as they were held in miles of queues until Operation Stack was lifted on Friday evening.
More than 3,000 lorries were parked on the M20 after the closure of the Port of Calais earlier this week crippled Channel sailings.
The chaos was sparked after MyFerryLink workers started a wildcat strike on Monday in protest at expected job cuts in the French port city.
The Port of Dover said no ferry traffic was being held in Operation Stack and there were full services to the Port of Calais and Dunkirk, Kazinform refers to BBC.com
