London: A small boat laden with migrants capsized in the dark in the English Channel Wednesday, killing four and increasing calls on the British government to do more to prevent people from risking their lives trying to cross one of the world's busiest shipping lanes.

Helicopters and lifeboats raced from bases in southern England after authorities received reports of a small boat in difficulty in waters between Britain and France just after 3 am local time.

Britain's Press Association, citing government sources, said 43 people were rescued, with more than 30 of those pulled from the water.

The operation was coordinated by the UK Maritime and Coastguard Agency and included personnel from both Britain and France.

It was unclear whether there were any more people missing.

Investigations are ongoing and we will provide further information in due course, the government said in a statement.

This is a truly tragic incident.

The British government has been under pressure to stop the smugglers, who charge migrants thousands of dollars each to cross the Channel in flimsy inflatable boats after at least 27 people died when their craft sank in November of last year. Prime Minister Rishi Sunak and his predecessors have gone as far as threatening to deport those entering the country illegally to Rwanda in an effort to dissuade people from making the crossing.

But the numbers keep rising as the prospect of work and education in Britain lures both economic migrants and those fleeing war, persecution and famine.

Some 44,000 people have made the journey so far this year, compared to 23,000 in all last year and 8,500 in 2020, according to government figures.

Sunak pledged Tuesday to clear the backlog of asylum applications and announced new measures aimed at curbing the number of migrants crossing the Channel.

Sunak said he planned to introduce legislation early next year to ensure people who arrive illegally cannot remain in the country.

The prime minister also said he was adding hundreds of workers to process asylum claims and clear the backlog, estimated at more than 143,000 pending applications, by the end of 2023.

The extra staff will also focus on the swift removal of Albanian migrants who come from a country Britain considers safe but are crossing the Channel in increasing numbers, Sunak said.