William J. McCarthy Jr., executive director of Catholic Charities in Maryland, said the leaders decided to break into four work groups focused on different aspects of the surge in child immigration. He said four topics will be: identifying financial resources, arranging for services such as medical and dental care and legal advice, short-term group shelter, and foster care.

Catholic Charities has been seeking to house 50 children from Central America at St. Vincent's Villa, a residential facility on Dulaney Valley Road in Baltimore County.

McCarthy said it's difficult to estimate how many Central American children will wind up in Maryland because it depends on future trends at the border. But with about half of the children who crossed having been placed, he said it's reasonable to anticipate that Maryland could become at least a temporary home to another 2,000 to 3,000 – most of them through family reunification.

"Everyone is united that there is a humanitarian crisis and there is a moral imperative to take care of the children," McCarthy said.

O'Malley aides reiterated Monday that the governor's first preference after family reunification is to provide foster care for underage immigrants. Only as a last resort would Maryland shelter them in group homes, the aides said. Even in that case, they said, the governor favors smaller facilities over larger ones.

The administration has acknowledged the possibility that some "congregate housing" could be located in Maryland as a way station before children are placed with families. However, administration officials did not identify any potential sites Monday other than St. Vincent's. They did, however, acknowledge that they were talking with local officials about potential group shelter sites.

In Montgomery County, home of one of Maryland's largest Central American communities, officials are considering a number of sites. They hope to find one in coming days that could house about 20 children, said county spokesman Patrick Lacefield. He would not say where the potential sites are located.

The spike in the number of unaccompanied children crossing the southern border has strained the country's resources for caring for them. Officials expect the number to reach 90,000 by the end of September amid continuing violence in Central America.

While some conservatives have called for the speedy deportation of the young immigrants, federal law requires that children who come here from nations other than Canada and Mexico without authorization be given an immigration hearing to determine whether they may meet U.S. criteria to stay.

In part because of the scope of the increase in crossings – and the added resources required to vet individual families – there has been little talk at the federal level so far of placing children who don't have family in the country already with foster families rather than keeping them at shelters temporarily.

The Obama administration is requesting Congress approve billions in new funding to deal with the influx of minors. The version of that legislation supported by Senate Democratic leaders would allocate $1.2 billion to bolster shelter capacity nationally.

Federal health officials have warned that without additional capacity, more children will be forced to stay at border detention facilities intended for adults.

Even without a group shelter, Maryland has been quietly absorbing a large number of the new immigrants. According to the Health and Human Services Department, between Jan. 1 and July 7 Maryland took in 2,205 unaccompanied immigrant children as their cases work their way through immigration proceedings.

That means that on a per capita basis, Maryland has had more unaccompanied immigrant children settled with sponsors than any other state. Administration officials said that is a result of the high proportion of Maryland residents who come from El Salvador, Honduras and Guatemala — the countries most of the immigrant children are fleeing.

Baltimore Sun reporter John Fritze contributed to this article.