French police said they had prevented more than 1,000 desperate attempts by migrants to get into Britain via the Channel Tunnel Friday, as London vowed further measures to tackle the crisis.
"More than 1,000 attempts were thwarted last night, with around 30 arrests," the source said, adding there were no reports of migrants injured in their bid to enter the undersea tunnel linking France and Britain.
Police reinforcements appeared to be having an impact, as the number of nightly attempts to penetrate the Eurotunnel premises has roughly halved since its peak at the beginning of the week.
France has sent 120 additional police officers to the northern port city of Calais to stem the crisis, as the number of deaths since June reached 10.
One man died in the early hours of Wednesday, apparently crushed by a lorry as he tried to make it into the tunnel.
A spokesman for Eurotunnel said there had been "much less disruption" since the reinforcements arrived to bolster the 300-strong police contingent already stationed in the city.
At least four coaches of riot police were on Friday morning guarding the entrance to the tunnel, where the situation was calm.
"I didn\’t make it into the station this time… It was very difficult, there was much more security than on previous days," said 20-year-old Reza from Afghanistan, rubbing his eyes after a short night\’s sleep as he stepped out of his tent.
"We didn\’t have a chance last night. There were too many policemen, even more than before," said Baby, 27, from Eritrea, who has been in camping out in Calais for more than two years.
A police source said that, while the reinforcements had helped, "the pressure of the migrants is still there" and the "situation remains difficult to deal with".
However, this source said there had been far fewer migrants managing to enter the Eurotunnel platforms and get on the train shuttles going to England.
During the night, an AFP journalist saw people descend onto the railways close to the Eurotunnel site only to be halted by police.
At least a dozen made it past the cordon, but ran straight into a second line of officers waiting a hundred metres (yards) further down the line.
Around 3,000 people from countries including Syria and Eritrea are waiting in Calais as they try to cross into Britain illegally by clambering on board lorries and trains.
Adding to the Calais difficulties, hundreds of French sailors blocked the city on Friday, using burning tyres to prevent access to the port in the midst of the peak holiday travel period.
The roughly 300 workers from French company Scop SeaFrance are protesting against plans to sell off some of their ferries to rival Danish firm DFDS, a move expected to result in hundreds of job losses.
Jean-Marc Puissesseau, president of the port of Calais, on Friday branded the latest action "the straw that broke the camel\’s back", and accused authorities of "abandoning" the port.
The crisis has become a hot political issue on both sides of the Channel and British Prime Minister David Cameron held a meeting of his government\’s COBRA emergency committee on Friday on the crisis.
After the meeting, Cameron vowed more security fencing and sniffer dogs to aid French police.
"The situation is not acceptable… We\’re going to put in more fencing, more resources, more sniffer dog teams," Cameron said, warning that the cross-Channel migrants issue would last for the next few months.
"I\’ll be speaking to President (Francois) Hollande later today. I want to thank him for the extra police resources that have been put in, which have had some effect."
"We are keen to offer more and work hand in glove with them to reduce pressure on that side of the border."
Hollande confirmed he would be speaking with Cameron, and told reporters that "everyone must take responsibility".
Cameron has come under fire for controversial comments on the crisis that has dominated British media all week, with furious truck drivers blocked on the English side of the channel.
Speaking on a visit to Vietnam, Cameron referred to a "swarm of people" wanting to come to his country to seek better lives and find employment.
The prime minister\’s comments earned him criticism from acting opposition Labour Party leader Harriet Harman, who said Cameron should "remember he is talking about people, not insects".
The Refugee Council, a leading British charity which works with asylum seekers, said it was "awful, dehumanising language from a world leader".
London has pledged £7 million (10 million euros, $11 million) to improve fencing around the Eurotunnel rail terminal at Coquelles, northern France.
Cameron also said that defence ministry land would be used to park trucks waiting to cross to Calais.