The company that operates the tunnel between France and England says more than 37,000 attempts by migrants to cross have been blocked since January.

Eurotunnel's statement comes after two successive nights of mass attempts to breach the tunnel by some of the thousands of migrants camped in northern France, hoping to reach a better life in England.

The company has come under increasing pressure to demonstrate its efforts to police the tunnel, which is a major conduit for both cargo and passengers between France and England.

For the most part, migrants caught trying to enter the tunnel are released almost immediately. Their camps hold about 3,000 people.