CALAIS, France — Top European migration officials held an emergency meeting Sunday in the French port of Calais to find ways to better fight migrant smuggling, after 27 people died trying to cross the English Channel to Britain in an overcrowded inflatable boat.

U.K. officials were notably absent from the gathering at the Calais City Hall, after Wednesday’s sinking prompted a new political crisis between Britain and France. The neighbors accuse each other of not doing enough to deter people from taking the treacherous journey.

British Home Secretary Priti Patel said it was “unfortunate” that she was uninvited to the meeting, and reiterated Britain’s proposal for returning migrants to France. French officials firmly rejected the idea when it was initially proposed, and said Britain was no longer welcome at Sunday’s talks.

France is carrying out an organized crime investigation into the sinking — the deadliest migration accident on the Channel on record. Iraqi Kurds and at least one Somali were among those aboard, though most have not been publicly identified.

Government ministers from Germany, the Netherlands, Belgium and France met in Calais with officials from the European Union, the EU border agency Frontex and the police agency Europol. They are focusing on smuggling networks, who charge from 3,000 to 7,000 euros ($3,400 to $7,900) for the journey across the Channel. France’s interior minister, Gérald Darmanin, said a car with German license tags was seized in connection with the investigation.

Earlier Sunday, Patel met with Dutch Migration Minister Ankie Broekers-Knol and stressed “the need for European partners to work together” through shared intelligence and joint police initiatives, according to her office.

“Both agreed that return agreements are essential for breaking the criminal business model,” it said.

The EU home affairs commissioner, Ylva Johansson, tweeted that fighting smugglers is “key” to any solution, and called for a common approach. EU countries have long argued over how to manage migration.

Aid groups, meanwhile, are arguing for more humane, coordinated asylum policies instead of just more police. At makeshift camps along the French coast, clusters of people from Sudan, Iran and Iraq huddle under the chilly rain, waiting for their chance to cross the Channel. They’re undeterred by Wednesday’s deaths or the stepped-up beach patrols.

The number of migrants trying to cross the channel in small boats has jumped this year, amid pandemic travel restrictions and after Britain’s Brexit departure from the EU. Overall, however, the number of migrants arriving in Britain is low compared with other European countries.