Facebook is profiting from child trafficking, Theresa May has revealed, as she warned that people smugglers were advertising “travel agent-style” services online to migrants.

At a meeting of EU leaders, the Prime Minister pledged to crack down on the practice, which is contributing to the death toll as people try to cross the Mediterranean from Africa to Europe in search of a new life.

Mrs May accused Facebook and other social media companies of failing to tackle the problem because of how easy it was for trafficking gangs to post convincing advertisements online without them being removed.

Some were even promising discounts for children, government research found.

This allowed vulnerable people to believe they were paying for a “safe, normal” form of travel to reach Europe, she said.