— European police have busted a human smuggling ring said to be part of a network transporting thousand of migrants in life-threatening conditions across the Channel to Britain.

Law officers, working together with Europe's policing and judicial agencies Europol and Eurojust arrested 12 suspected smugglers over the last two days, The Hague-based Eurojust said in a statement on Wednesday.

"Twelve suspects were arrested in the combined operation including seven in France, three in Britain and two in The Netherlands," it said.

Police also seized 12 vehicles, 10 rubber boats and engines, 152 life jackets, a caravan, a boat trailer, jewellery, about 48,000 euros ($56,000) in cash, documents and mobile devices, Eurojust said.

Those arrested are suspected of being part of a mainly Iranian organised smuggling gang based in France, The Netherlands and Britain, organising their activities through their ties in the various countries.

"The network is believed to have made huge profits from smuggling migrants in small boats from the north coasts of France to Britain," charging an average of 3,000 euros per crossing, Eurojust said.

"Transporting migrants in overloaded boats, often in very difficult weather conditions on one of the busiest commercial shipping lanes in the world, endangered the lives of both the migrants and also the law enforcement officers conducting sea rescue operations," it said.

Eurojust said illegal migrant-smuggling activity has "increased exponentially" in recent months with over 4600 irregular migrants detected since 2018 on British shores.

The combined operation comes as French police on Tuesday dismantled a camp of about 800 migrants in the port city of Calais.

Calais continues to attract migrants from the Middle East and Africa who set up makeshift camps along France's northern coast from where they hope to make the passage across the English Channel to Britain.

Since January 1, French authorities have intercepted at least 1,317 migrants as they tried to reach the UK, some by swimming across the busy waterway.

In August, a Sudanese teenager drowned while trying to reach Britain with a friend in an inflatable boat