BRUSSELS — When Belgium went into lockdown in mid-March because of the coronavirus pandemic, the authorities emptied half of the country’s migrant detention centers to help prevent the spread of the virus, leaving hundreds of people without a home.

The government also closed the reception center in Brussels that registers new asylum seekers, making it impossible for them to get state support. Since then, the application process was reopened this month — but only online and only in French and Dutch, making it nearly inaccessible to asylum seekers.

“This excludes the majority of people,” said Mehdi Kassou, a founder of Citizens’ Platform for the Support of Refugees, which offers services and emergency housing. “It is just a fig leaf for the government’s inaction.”

The migrants, most of whom are in transit and largely unregistered, hope to make it to Britain, often by smuggling themselves there. But these days, with border closures and travel restrictions, they are stuck in Belgium with little recourse.