British Prime Minister Boris Johnson and French President Emmanuel Macron have agreed to strengthen cooperation between their two countries to combat irregular migration through the Channel Channel, after 27 migrants drowned while trying to reach Britain.

A British government spokesman said that Johnson and Macron stressed during a telephone conversation between them on Wednesday evening the urgent need to increase joint efforts to prevent crossings across the Channel, and to do everything possible to stop criminal gangs that endanger people's lives.

The phone call between the British Prime Minister and the French President comes hours after the bodies of 27 migrants were found dead after a boat capsized from northern France in an attempt to reach Britain via the English Channel.

An initial toll reported the death of 31 migrants and the loss of two others, but the French authorities confirmed on Wednesday evening that 27 had died and two others had survived.

Earlier on Wednesday, the French president demanded an immediate reinforcement of the Frontex agency, which is tasked with guarding the borders of the European Union, stressing that his country would not let the English Channel turn into a cemetery.

Macron also called for an urgent meeting of European ministers in charge of what he described as the challenge of migration and asylum, saying that Paris will work to find and hold accountable those responsible for the tragedy of the drowning of migrants.

For his part, the British Prime Minister expressed his shock over the sinking of migrants in the Channel Channel and demanded to redouble efforts to stop the work of human smuggling gangs.

Johnson vowed to wage war on human trafficking gangs, in reference to the organizers of irregular migration across the English Channel between France and Britain.

France and Britain had carried out searches in the English Channel, involving ships and helicopters, to find possible survivors.

Items left by migrants on a beach in northern France (Reuters)

worst accident

Officials described the drowning of irregular migrants in the Channel as the worst of its kind in the waterway separating Britain and France, with the largest death toll since the number of crossings across the Channel rose in 2018.

French Interior Minister Gerald Darmanan announced from Calais (northern France) the arrest of 4 suspected smugglers of migrants in connection with the sinking of the boat in the English Channel, calling for a strong and serious international response to the migration issue.

For his part, French Prime Minister Jean Castix described the drowning of migrants as a tragedy.

Simultaneously, the Public Prosecutor's Office in Dunkirk (Northern France) announced the opening of an investigation into "assisting illegal stay in the framework of the activity of a criminal gang", and "described unintentional murder".

The bodies of the victims were taken to the port of Calais, and the Associated Press quoted a judicial official in the city of Lille that authorities are working to determine the identities, ages and nationalities of the victims.

In the vicinity of the port, activists demonstrated late on Wednesday, accusing governments of not doing enough to meet the needs of migrants.

Hundreds of irregular migrants live in harsh conditions on the shores of France, waiting for an opportunity to leave the country.

Prior to this incident, the death toll in the English Channel since the beginning of this year was 3 dead and 4 missing.

Last year, 6 people were killed and 3 are missing, compared to 4 people killed in 2019.