The number of migrants trying to enter Britain from France through the Eurotunnel, eased slightly over Wednesday night, compared to earlier in the week.
A police officer said there were around 800 migrants around the site with roughly 300 intercepted.
Attempts by migrants, mainly from the Middle East and Africa have forced Britain and France to cooperate to find a long-term solution to the issue.
France has deployed more than 100 riot police to the port of Calais to bolster its security.
Meanwhile, Britain has said it is erecting a three-meter fence to protect the terminal. French media say nine migrants have died since early June in attempts to cross the tunnel.
Eurotunnel officials said that more than 37,000 such attempts by migrants had been blocked since January.